return new AssignOperator(outputVariable, nodeTreeIdExpression);
}
private GroupByOperator getGroupByOperator(LogicalVariable outputVariable, ILogicalExpression variableRef) {
GroupByOperator op = new GroupByOperator();
op.addGbyExpression(outputVariable, variableRef);
return op;
}
private Mutable<ILogicalOperator> getInputOperator(Mutable<ILogicalOperator> opRef) {
AbstractLogicalOperator op = (AbstractLogicalOperator) opRef.getValue();