@Override
  public void beforeIterationEvaluation(CompiledValue executer, Object currentObject) {}
Called once before the evaluation of an expression for a single iteration of a 'select'
statment. The RuntimeIterator that was passed to startIteration should already be referencing
the current iteration value.

@param executer the object performing the iteration.
@param currentObject The current object in the iteration.
geode-core/src/main/java/org/apache/geode/cache/query/internal/QueryObserverAdapter.java