error java.util.NoSuchElementException: key not found for version 1.7

[seralf]

Hi using version 1.7 of morph-querygen like this:

val conf = ConfigFactory.load("application.conf").getConfig("r2rml").resolve()
val morph = Morph.createJdbcModel
val ds = morph.generate(conf.getString("mapping"))

I obtained the following error:

Exception in thread "main" java.util.NoSuchElementException: key not found: TITLETITLE

Where the corresponding snippet in the mapping is similar to the following:

rr:predicateObjectMap   [ 
    rr:predicate   dc:title   ;
    rr:objectMap   [   rr:column   "TITLE"   ] 
]   ; 

As you can see, it seems that the column name is duplicated for some reason. Maybe it is an issue introduced by mistake by my last pull request, as it does not seem to affect version 1.6, but inspecting the code I was not able to find the place where the problem begins, it seems somewaht related to method: upm.fi.oeg.morph.execute.TripleGenerator.generate(subj: Resource, rs: Dataset)