/** * Try to match the given operator pattern.. * * @param operator the operator that should be matched with the operator pattern */ private void attemptMatchFrom(Operator operator, InputSlot<?> fromInputSlot, OutputSlot<?> fromOutputSlot) { Validate.isTrue(fromInputSlot == null, "Cannot handle downstream traversals."); // Try to make a match starting from the currently visited operator. final SubplanMatch subplanMatch = new SubplanMatch(SubplanPattern.this); this.match(SubplanPattern.this.outputPattern, operator, fromOutputSlot, subplanMatch); }