public static void removeOperator(Operator<?> target, ParseContext context) {
    assert target.getNumParent() == 1 && target.getNumChild() == 1;
    removeOperator(target,
        target.getChildOperators().get(0), target.getParentOperators().get(0), context);
  }
@param newOperator the operator will be inserted between child and parent
@param child
@param parent
@throws SemanticException
ql/src/java/org/apache/hadoop/hive/ql/optimizer/correlation/CorrelationUtilities.java