COLLECTIONS-873: create PatriciaTrieSet

[ekuvardin]

According to https://issues.apache.org/jira/browse/COLLECTIONS-873

MR is basically a draft or discussion of what to do.

I make PatriciaTrieSet based on PatriciaTrie under the hood.

Below I type what I don't like. Please give some advice.

The main problem is when I access PatriciaTrie, I have to return SortedSet.
But all collections under the hood of PatriciaTrie don't use SortedSet.
Thus, I wrap call under TreeSet.

For example

@Override
    public SortedSet<String> headSet(String toElement) {
        return new TreeSet<>(trie.headMap(toElement).keySet());
    }

This is overwhelming because the keySet is already sorted, and adding to a TreeSet also takes time.

To improve the situation, I make two approaches:

1. Fully rewrite PatriciaTrieSet, copying logic with bit operations to the corresponding class.
   The drawback is that a change (bug) in bit operations leads to a rewrite in PatriciaTrieSet and PatriciaTrie independently.
2. Extend the internal PatricaiTrie class to implement NavigableMap (PrefixRangeMap and RangeEntryMap + some other classes).
   public interface NavigableMap<K,V> extends SortedMap<K,V>
   From NavigableMap, I can get navigableKeySet and work with it in PatriciaTrieSet.

[garydgregory]

Hello @ekuvardin
The build fails, it seems you did not read or follow the steps in https://github.com/apache/commons-collections/blob/master/.github/pull_request_template.md

[ekuvardin]

@garydgregory
Fix build. My fault forget for Apache license header and manually disable rat check

Now:

1. Localy run mvn with no errors
2. Checkstyle doesn't add new warning on new files
3. Make more unit test
4. Make benchmarks. I don't find JMH benchmarks in the project and write on my own.
   https://github.com/ekuvardin/apache-common-collections-benchmarks
   Goal: Approve that set, give some additional time to work, and performance on each method doesn't degrade dramatically.

Benchmarks results

Benchmark                                             (sizeFill)  Mode  Cnt    Score   Error  Units
PatriciaBenchmarkAddExistingValue.addPatriciaTrie          10000  avgt   10  132,648 ? 1,718  ns/op
PatriciaBenchmarkAddExistingValue.addPatriciaTrieSet       10000  avgt   10  141,382 ? 2,160  ns/op

Benchmark                                        (sizeFill)  (sizeTryToAdd)  Mode  Cnt    Score   Error  Units
PatriciaBenchmarkAddNewValue.addPatriciaTrie          10000          100000  avgt    5  158,198 ? 1,014  ns/op
PatriciaBenchmarkAddNewValue.addPatriciaTrieSet       10000          100000  avgt    5  175,539 ? 3,196  ns/op

Benchmark                                      (sizeFill)  (sizeTryToRemove)  Mode  Cnt    Score   Error  Units
PatriciaBenchmarkRemove.removePatriciaTrie         100000             100000  avgt    5  133,199 ? 0,989  ns/op
PatriciaBenchmarkRemove.removePatriciaTrieSet      100000             100000  avgt    5  134,057 ? 0,960  ns/op

Benchmark                                                            (size)  Mode  Cnt        Score       Error  Units
PatriciaBenchmarkSimpleOperation.containsPatriciaTrie                  1000  avgt    5       48,596 ?     1,230  ns/op
PatriciaBenchmarkSimpleOperation.containsPatriciaTrie                 10000  avgt    5       51,476 ?     0,824  ns/op
PatriciaBenchmarkSimpleOperation.containsPatriciaTrie                100000  avgt    5       51,834 ?     0,413  ns/op
PatriciaBenchmarkSimpleOperation.containsPatriciaTrieSet               1000  avgt    5       48,540 ?     1,174  ns/op
PatriciaBenchmarkSimpleOperation.containsPatriciaTrieSet              10000  avgt    5       52,369 ?     0,398  ns/op
PatriciaBenchmarkSimpleOperation.containsPatriciaTrieSet             100000  avgt    5       52,190 ?     0,547  ns/op
PatriciaBenchmarkSimpleOperation.firstPatriciaTrie                     1000  avgt    5        6,270 ?     0,093  ns/op
PatriciaBenchmarkSimpleOperation.firstPatriciaTrie                    10000  avgt    5        6,262 ?     0,061  ns/op
PatriciaBenchmarkSimpleOperation.firstPatriciaTrie                   100000  avgt    5        6,230 ?     0,187  ns/op
PatriciaBenchmarkSimpleOperation.firstPatriciaTrieSet                  1000  avgt    5        6,817 ?     0,066  ns/op
PatriciaBenchmarkSimpleOperation.firstPatriciaTrieSet                 10000  avgt    5        6,751 ?     0,088  ns/op
PatriciaBenchmarkSimpleOperation.firstPatriciaTrieSet                100000  avgt    5        6,737 ?     0,085  ns/op
PatriciaBenchmarkSimpleOperation.headMapPatriciaTrie                   1000  avgt    5        6,687 ?     0,023  ns/op
PatriciaBenchmarkSimpleOperation.headMapPatriciaTrie                  10000  avgt    5        6,808 ?     0,231  ns/op
PatriciaBenchmarkSimpleOperation.headMapPatriciaTrie                 100000  avgt    5        6,819 ?     0,319  ns/op
PatriciaBenchmarkSimpleOperation.headSetPatriciaTrieSet                1000  avgt    5        9,267 ?     0,075  ns/op
PatriciaBenchmarkSimpleOperation.headSetPatriciaTrieSet               10000  avgt    5        9,343 ?     0,211  ns/op
PatriciaBenchmarkSimpleOperation.headSetPatriciaTrieSet              100000  avgt    5        9,330 ?     0,154  ns/op
PatriciaBenchmarkSimpleOperation.isEmptyPatriciaTrie                   1000  avgt    5        0,792 ?     0,019  ns/op
PatriciaBenchmarkSimpleOperation.isEmptyPatriciaTrie                  10000  avgt    5        0,799 ?     0,005  ns/op
PatriciaBenchmarkSimpleOperation.isEmptyPatriciaTrie                 100000  avgt    5        0,889 ?     0,060  ns/op
PatriciaBenchmarkSimpleOperation.isEmptyPatriciaTrieSet                1000  avgt    5        1,021 ?     0,180  ns/op
PatriciaBenchmarkSimpleOperation.isEmptyPatriciaTrieSet               10000  avgt    5        1,186 ?     0,195  ns/op
PatriciaBenchmarkSimpleOperation.isEmptyPatriciaTrieSet              100000  avgt    5        1,024 ?     0,155  ns/op
PatriciaBenchmarkSimpleOperation.iteratorPatriciaTrie                  1000  avgt    5    10405,896 ?   202,444  ns/op
PatriciaBenchmarkSimpleOperation.iteratorPatriciaTrie                 10000  avgt    5   123151,828 ? 34419,185  ns/op
PatriciaBenchmarkSimpleOperation.iteratorPatriciaTrie                100000  avgt    5  1727588,628 ? 25520,548  ns/op
PatriciaBenchmarkSimpleOperation.iteratorPatriciaTrieSet               1000  avgt    5    10049,078 ?   130,071  ns/op
PatriciaBenchmarkSimpleOperation.iteratorPatriciaTrieSet              10000  avgt    5   141096,432 ?  1309,961  ns/op
PatriciaBenchmarkSimpleOperation.iteratorPatriciaTrieSet             100000  avgt    5  1664385,856 ?  8252,919  ns/op
PatriciaBenchmarkSimpleOperation.iteratorSubSetPatriciaTrie            1000  avgt    5     6866,638 ?   235,368  ns/op
PatriciaBenchmarkSimpleOperation.iteratorSubSetPatriciaTrie           10000  avgt    5    27320,421 ?   359,976  ns/op
PatriciaBenchmarkSimpleOperation.iteratorSubSetPatriciaTrie          100000  avgt    5   718470,198 ? 16591,016  ns/op
PatriciaBenchmarkSimpleOperation.iteratorSubSetPatriciaTrieSet         1000  avgt    5     7169,227 ?    51,483  ns/op
PatriciaBenchmarkSimpleOperation.iteratorSubSetPatriciaTrieSet        10000  avgt    5    27232,041 ?   819,069  ns/op
PatriciaBenchmarkSimpleOperation.iteratorSubSetPatriciaTrieSet       100000  avgt    5   742578,217 ?  5893,876  ns/op
PatriciaBenchmarkSimpleOperation.lastPatriciaTrie                      1000  avgt    5       16,504 ?     0,077  ns/op
PatriciaBenchmarkSimpleOperation.lastPatriciaTrie                     10000  avgt    5       16,445 ?     0,250  ns/op
PatriciaBenchmarkSimpleOperation.lastPatriciaTrie                    100000  avgt    5       23,058 ?     0,407  ns/op
PatriciaBenchmarkSimpleOperation.lastPatriciaTrieSet                   1000  avgt    5       18,047 ?     0,138  ns/op
PatriciaBenchmarkSimpleOperation.lastPatriciaTrieSet                  10000  avgt    5       17,766 ?     0,502  ns/op
PatriciaBenchmarkSimpleOperation.lastPatriciaTrieSet                 100000  avgt    5       24,725 ?     0,513  ns/op
PatriciaBenchmarkSimpleOperation.prefixMapPatriciaTrie                 1000  avgt    5        8,907 ?     0,046  ns/op
PatriciaBenchmarkSimpleOperation.prefixMapPatriciaTrie                10000  avgt    5        8,943 ?     0,153  ns/op
PatriciaBenchmarkSimpleOperation.prefixMapPatriciaTrie               100000  avgt    5        8,887 ?     0,013  ns/op
PatriciaBenchmarkSimpleOperation.prefixSetPatriciaTrieSet              1000  avgt    5       11,372 ?     0,046  ns/op
PatriciaBenchmarkSimpleOperation.prefixSetPatriciaTrieSet             10000  avgt    5       11,398 ?     0,036  ns/op
PatriciaBenchmarkSimpleOperation.prefixSetPatriciaTrieSet            100000  avgt    5       11,341 ?     0,012  ns/op
PatriciaBenchmarkSimpleOperation.sizePatriciaTrie                      1000  avgt    5        0,948 ?     0,119  ns/op
PatriciaBenchmarkSimpleOperation.sizePatriciaTrie                     10000  avgt    5        0,803 ?     0,052  ns/op
PatriciaBenchmarkSimpleOperation.sizePatriciaTrie                    100000  avgt    5        0,889 ?     0,073  ns/op
PatriciaBenchmarkSimpleOperation.sizePatriciaTrieSet                   1000  avgt    5        1,038 ?     0,137  ns/op
PatriciaBenchmarkSimpleOperation.sizePatriciaTrieSet                  10000  avgt    5        1,102 ?     0,201  ns/op
PatriciaBenchmarkSimpleOperation.sizePatriciaTrieSet                 100000  avgt    5        1,250 ?     0,248  ns/op
PatriciaBenchmarkSimpleOperation.subMapPatriciaTrie                    1000  avgt    5        8,460 ?     0,051  ns/op
PatriciaBenchmarkSimpleOperation.subMapPatriciaTrie                   10000  avgt    5        8,982 ?     0,036  ns/op
PatriciaBenchmarkSimpleOperation.subMapPatriciaTrie                  100000  avgt    5        8,413 ?     0,044  ns/op
PatriciaBenchmarkSimpleOperation.subMapPatriciaTrieContains            1000  avgt    5       25,776 ?     0,592  ns/op
PatriciaBenchmarkSimpleOperation.subMapPatriciaTrieContains           10000  avgt    5       26,233 ?     0,247  ns/op
PatriciaBenchmarkSimpleOperation.subMapPatriciaTrieContains          100000  avgt    5       26,073 ?     0,307  ns/op
PatriciaBenchmarkSimpleOperation.subMapPatriciaTrieSetContains         1000  avgt    5       26,864 ?     0,812  ns/op
PatriciaBenchmarkSimpleOperation.subMapPatriciaTrieSetContains        10000  avgt    5       27,708 ?     0,398  ns/op
PatriciaBenchmarkSimpleOperation.subMapPatriciaTrieSetContains       100000  avgt    5       26,643 ?     0,286  ns/op
PatriciaBenchmarkSimpleOperation.subSetPatriciaTrieSet                 1000  avgt    5       11,157 ?     0,400  ns/op
PatriciaBenchmarkSimpleOperation.subSetPatriciaTrieSet                10000  avgt    5       11,364 ?     0,049  ns/op
PatriciaBenchmarkSimpleOperation.subSetPatriciaTrieSet               100000  avgt    5       11,009 ?     0,293  ns/op
PatriciaBenchmarkSimpleOperation.tailMapPatriciaTrie                   1000  avgt    5        6,842 ?     0,057  ns/op
PatriciaBenchmarkSimpleOperation.tailMapPatriciaTrie                  10000  avgt    5        6,839 ?     0,034  ns/op
PatriciaBenchmarkSimpleOperation.tailMapPatriciaTrie                 100000  avgt    5        6,850 ?     0,029  ns/op
PatriciaBenchmarkSimpleOperation.tailSetPatriciaTrieSet                1000  avgt    5        9,305 ?     0,007  ns/op
PatriciaBenchmarkSimpleOperation.tailSetPatriciaTrieSet               10000  avgt    5        9,508 ?     0,196  ns/op
PatriciaBenchmarkSimpleOperation.tailSetPatriciaTrieSet              100000  avgt    5        9,338 ?     0,036  ns/op

[ekuvardin]

Summary

How it works
The main idea is to build logic on the above existing PatriciaTrie not reinventing a wheel.
To do this, I create a stub Object and use it as a value in PatriciaTrie
static final Object PRESENT = new Object();
All put methods are similar to
patriciaTrie .put(e, PRESENT)

All new classes are put on a picture below.

TrieSet
New interface TrieSet consists of methods.
SortedSet<K> prefixSet(K key);
and extends
SortedSet

PatriciaTrieSet
New class PatriciaTrieSet
implements
TrieSet<String>
extends

AbstractSet<String>
Serializable 

RangePatriciaTrieSortedSet
User will want to work with results of methods below in a SortedSet manner.

SortedSet<E> subSet(E fromElement, E toElement);
SortedSet<E> headSet(E toElement);
SortedSet<E> tailSet(E fromElement);
SortedSet<K> prefixSet(K key);

To do so, I create an inner class RangePatriciaTrieSortedSet in PatriciaTrieSet
extends
AbstractSet<String>
implements
SortedSet<String>

RangePatriciaTrieSortedSet doesn't immediately construct SortedSet; it's a wrapper under PatriciaSet.RangeEntryMap and PatriciaSet.PrefixRangeMap works in the same manner.

Objects in this SortedMap are sorted according to lexicographical order.
Objects in SortedSet just ignore value.

Benchmarks
Also write some benchmarks to prove that Set doesn't degrade dramatically.
Make benchmarks. I don't find JMH benchmarks in the project and write on my own.
https://github.com/ekuvardin/apache-common-collections-benchmarks

Benchmarks results

Benchmark                                             (sizeFill)  Mode  Cnt    Score   Error  Units
PatriciaBenchmarkAddExistingValue.addPatriciaTrie          10000  avgt   10  132,648 ? 1,718  ns/op
PatriciaBenchmarkAddExistingValue.addPatriciaTrieSet       10000  avgt   10  141,382 ? 2,160  ns/op

Benchmark                                        (sizeFill)  (sizeTryToAdd)  Mode  Cnt    Score   Error  Units
PatriciaBenchmarkAddNewValue.addPatriciaTrie          10000          100000  avgt    5  158,198 ? 1,014  ns/op
PatriciaBenchmarkAddNewValue.addPatriciaTrieSet       10000          100000  avgt    5  175,539 ? 3,196  ns/op

Benchmark                                      (sizeFill)  (sizeTryToRemove)  Mode  Cnt    Score   Error  Units
PatriciaBenchmarkRemove.removePatriciaTrie         100000             100000  avgt    5  133,199 ? 0,989  ns/op
PatriciaBenchmarkRemove.removePatriciaTrieSet      100000             100000  avgt    5  134,057 ? 0,960  ns/op

Benchmark                                                            (size)  Mode  Cnt        Score       Error  Units
PatriciaBenchmarkSimpleOperation.containsPatriciaTrie                  1000  avgt    5       48,596 ?     1,230  ns/op
PatriciaBenchmarkSimpleOperation.containsPatriciaTrie                 10000  avgt    5       51,476 ?     0,824  ns/op
PatriciaBenchmarkSimpleOperation.containsPatriciaTrie                100000  avgt    5       51,834 ?     0,413  ns/op
PatriciaBenchmarkSimpleOperation.containsPatriciaTrieSet               1000  avgt    5       48,540 ?     1,174  ns/op
PatriciaBenchmarkSimpleOperation.containsPatriciaTrieSet              10000  avgt    5       52,369 ?     0,398  ns/op
PatriciaBenchmarkSimpleOperation.containsPatriciaTrieSet             100000  avgt    5       52,190 ?     0,547  ns/op
PatriciaBenchmarkSimpleOperation.firstPatriciaTrie                     1000  avgt    5        6,270 ?     0,093  ns/op
PatriciaBenchmarkSimpleOperation.firstPatriciaTrie                    10000  avgt    5        6,262 ?     0,061  ns/op
PatriciaBenchmarkSimpleOperation.firstPatriciaTrie                   100000  avgt    5        6,230 ?     0,187  ns/op
PatriciaBenchmarkSimpleOperation.firstPatriciaTrieSet                  1000  avgt    5        6,817 ?     0,066  ns/op
PatriciaBenchmarkSimpleOperation.firstPatriciaTrieSet                 10000  avgt    5        6,751 ?     0,088  ns/op
PatriciaBenchmarkSimpleOperation.firstPatriciaTrieSet                100000  avgt    5        6,737 ?     0,085  ns/op
PatriciaBenchmarkSimpleOperation.headMapPatriciaTrie                   1000  avgt    5        6,687 ?     0,023  ns/op
PatriciaBenchmarkSimpleOperation.headMapPatriciaTrie                  10000  avgt    5        6,808 ?     0,231  ns/op
PatriciaBenchmarkSimpleOperation.headMapPatriciaTrie                 100000  avgt    5        6,819 ?     0,319  ns/op
PatriciaBenchmarkSimpleOperation.headSetPatriciaTrieSet                1000  avgt    5        9,267 ?     0,075  ns/op
PatriciaBenchmarkSimpleOperation.headSetPatriciaTrieSet               10000  avgt    5        9,343 ?     0,211  ns/op
PatriciaBenchmarkSimpleOperation.headSetPatriciaTrieSet              100000  avgt    5        9,330 ?     0,154  ns/op
PatriciaBenchmarkSimpleOperation.isEmptyPatriciaTrie                   1000  avgt    5        0,792 ?     0,019  ns/op
PatriciaBenchmarkSimpleOperation.isEmptyPatriciaTrie                  10000  avgt    5        0,799 ?     0,005  ns/op
PatriciaBenchmarkSimpleOperation.isEmptyPatriciaTrie                 100000  avgt    5        0,889 ?     0,060  ns/op
PatriciaBenchmarkSimpleOperation.isEmptyPatriciaTrieSet                1000  avgt    5        1,021 ?     0,180  ns/op
PatriciaBenchmarkSimpleOperation.isEmptyPatriciaTrieSet               10000  avgt    5        1,186 ?     0,195  ns/op
PatriciaBenchmarkSimpleOperation.isEmptyPatriciaTrieSet              100000  avgt    5        1,024 ?     0,155  ns/op
PatriciaBenchmarkSimpleOperation.iteratorPatriciaTrie                  1000  avgt    5    10405,896 ?   202,444  ns/op
PatriciaBenchmarkSimpleOperation.iteratorPatriciaTrie                 10000  avgt    5   123151,828 ? 34419,185  ns/op
PatriciaBenchmarkSimpleOperation.iteratorPatriciaTrie                100000  avgt    5  1727588,628 ? 25520,548  ns/op
PatriciaBenchmarkSimpleOperation.iteratorPatriciaTrieSet               1000  avgt    5    10049,078 ?   130,071  ns/op
PatriciaBenchmarkSimpleOperation.iteratorPatriciaTrieSet              10000  avgt    5   141096,432 ?  1309,961  ns/op
PatriciaBenchmarkSimpleOperation.iteratorPatriciaTrieSet             100000  avgt    5  1664385,856 ?  8252,919  ns/op
PatriciaBenchmarkSimpleOperation.iteratorSubSetPatriciaTrie            1000  avgt    5     6866,638 ?   235,368  ns/op
PatriciaBenchmarkSimpleOperation.iteratorSubSetPatriciaTrie           10000  avgt    5    27320,421 ?   359,976  ns/op
PatriciaBenchmarkSimpleOperation.iteratorSubSetPatriciaTrie          100000  avgt    5   718470,198 ? 16591,016  ns/op
PatriciaBenchmarkSimpleOperation.iteratorSubSetPatriciaTrieSet         1000  avgt    5     7169,227 ?    51,483  ns/op
PatriciaBenchmarkSimpleOperation.iteratorSubSetPatriciaTrieSet        10000  avgt    5    27232,041 ?   819,069  ns/op
PatriciaBenchmarkSimpleOperation.iteratorSubSetPatriciaTrieSet       100000  avgt    5   742578,217 ?  5893,876  ns/op
PatriciaBenchmarkSimpleOperation.lastPatriciaTrie                      1000  avgt    5       16,504 ?     0,077  ns/op
PatriciaBenchmarkSimpleOperation.lastPatriciaTrie                     10000  avgt    5       16,445 ?     0,250  ns/op
PatriciaBenchmarkSimpleOperation.lastPatriciaTrie                    100000  avgt    5       23,058 ?     0,407  ns/op
PatriciaBenchmarkSimpleOperation.lastPatriciaTrieSet                   1000  avgt    5       18,047 ?     0,138  ns/op
PatriciaBenchmarkSimpleOperation.lastPatriciaTrieSet                  10000  avgt    5       17,766 ?     0,502  ns/op
PatriciaBenchmarkSimpleOperation.lastPatriciaTrieSet                 100000  avgt    5       24,725 ?     0,513  ns/op
PatriciaBenchmarkSimpleOperation.prefixMapPatriciaTrie                 1000  avgt    5        8,907 ?     0,046  ns/op
PatriciaBenchmarkSimpleOperation.prefixMapPatriciaTrie                10000  avgt    5        8,943 ?     0,153  ns/op
PatriciaBenchmarkSimpleOperation.prefixMapPatriciaTrie               100000  avgt    5        8,887 ?     0,013  ns/op
PatriciaBenchmarkSimpleOperation.prefixSetPatriciaTrieSet              1000  avgt    5       11,372 ?     0,046  ns/op
PatriciaBenchmarkSimpleOperation.prefixSetPatriciaTrieSet             10000  avgt    5       11,398 ?     0,036  ns/op
PatriciaBenchmarkSimpleOperation.prefixSetPatriciaTrieSet            100000  avgt    5       11,341 ?     0,012  ns/op
PatriciaBenchmarkSimpleOperation.sizePatriciaTrie                      1000  avgt    5        0,948 ?     0,119  ns/op
PatriciaBenchmarkSimpleOperation.sizePatriciaTrie                     10000  avgt    5        0,803 ?     0,052  ns/op
PatriciaBenchmarkSimpleOperation.sizePatriciaTrie                    100000  avgt    5        0,889 ?     0,073  ns/op
PatriciaBenchmarkSimpleOperation.sizePatriciaTrieSet                   1000  avgt    5        1,038 ?     0,137  ns/op
PatriciaBenchmarkSimpleOperation.sizePatriciaTrieSet                  10000  avgt    5        1,102 ?     0,201  ns/op
PatriciaBenchmarkSimpleOperation.sizePatriciaTrieSet                 100000  avgt    5        1,250 ?     0,248  ns/op
PatriciaBenchmarkSimpleOperation.subMapPatriciaTrie                    1000  avgt    5        8,460 ?     0,051  ns/op
PatriciaBenchmarkSimpleOperation.subMapPatriciaTrie                   10000  avgt    5        8,982 ?     0,036  ns/op
PatriciaBenchmarkSimpleOperation.subMapPatriciaTrie                  100000  avgt    5        8,413 ?     0,044  ns/op
PatriciaBenchmarkSimpleOperation.subMapPatriciaTrieContains            1000  avgt    5       25,776 ?     0,592  ns/op
PatriciaBenchmarkSimpleOperation.subMapPatriciaTrieContains           10000  avgt    5       26,233 ?     0,247  ns/op
PatriciaBenchmarkSimpleOperation.subMapPatriciaTrieContains          100000  avgt    5       26,073 ?     0,307  ns/op
PatriciaBenchmarkSimpleOperation.subMapPatriciaTrieSetContains         1000  avgt    5       26,864 ?     0,812  ns/op
PatriciaBenchmarkSimpleOperation.subMapPatriciaTrieSetContains        10000  avgt    5       27,708 ?     0,398  ns/op
PatriciaBenchmarkSimpleOperation.subMapPatriciaTrieSetContains       100000  avgt    5       26,643 ?     0,286  ns/op
PatriciaBenchmarkSimpleOperation.subSetPatriciaTrieSet                 1000  avgt    5       11,157 ?     0,400  ns/op
PatriciaBenchmarkSimpleOperation.subSetPatriciaTrieSet                10000  avgt    5       11,364 ?     0,049  ns/op
PatriciaBenchmarkSimpleOperation.subSetPatriciaTrieSet               100000  avgt    5       11,009 ?     0,293  ns/op
PatriciaBenchmarkSimpleOperation.tailMapPatriciaTrie                   1000  avgt    5        6,842 ?     0,057  ns/op
PatriciaBenchmarkSimpleOperation.tailMapPatriciaTrie                  10000  avgt    5        6,839 ?     0,034  ns/op
PatriciaBenchmarkSimpleOperation.tailMapPatriciaTrie                 100000  avgt    5        6,850 ?     0,029  ns/op
PatriciaBenchmarkSimpleOperation.tailSetPatriciaTrieSet                1000  avgt    5        9,305 ?     0,007  ns/op
PatriciaBenchmarkSimpleOperation.tailSetPatriciaTrieSet               10000  avgt    5        9,508 ?     0,196  ns/op
PatriciaBenchmarkSimpleOperation.tailSetPatriciaTrieSet              100000  avgt    5        9,338 ?     0,036  ns/op

[ekuvardin]

Merge with master and fix new checkstyle warnings that come with the latest master commits.