@Override
  public void beforeMergeJoinOfDoubleIndexResults(Index index1, Index index2,
      Collection initialResult) {}
Asif :Invoked before merging the results of the two indexes, identified for evaluation of a
filter evalua table equi join condition across two regions ( Composite Condition). During this
merging the appropriate expansion & cutdown of the individual index results to the final query
level or CompositeGroupJunction level also occurs. Also for AND conditions, the cartesian with
the intermediate resultset will also occur.

@param index1 Range Index identified for one of the operand, to be used in equi join condition
@param index2 Range Index identified for the other operand , to be used in equi join condition
@param initialResult A list in which each element contains a TWO dimensional Object array
       containing two rows. First row contains Index Resultset obtained from 1st index & second
       row contains results obtained from second index. Each element of the list basically
       represents an equi join satisfying value ( i.e something like 1 = 1, 2 = 2 , 3 = 3 )
       etc. Since multiple objects of a region can have same value , so there exits rows of
       Object Array for each Index.
geode-core/src/main/java/org/apache/geode/cache/query/internal/QueryObserverAdapter.java