Make random variable initialized only once

Author: Diamondback88

api/src/main/java/parallelmc/parallelutils/util/RandomTools.java

@@ -7,14 +7,19 @@
  */
 public class RandomTools {
 
+    private static Random r;
+
+    private RandomTools() {
+        r = new Random();
+    }
+
     /**
      * Calculates a random integer between two integer values
      * @param low The first integer
      * @param high The second integer
      * @return The random integer between low and high, inclusive
      */
     public static int betweenTwoNumbers(int low, int high) {
-        Random r = new Random();
         return r.nextInt(high - low + 1) + low;
     }
 }