@Override
public PhysicalOperator getPhysicalOperator(PhysicalPlanCreator creator) throws IOException {
Prel child = (Prel) this.getChild();
PhysicalOperator childPOP = child.getPhysicalOperator(creator);
FlattenPOP f = new FlattenPOP(childPOP, (SchemaPath) getFlattenExpression(new DrillParseContext()));
return creator.addMetadata(this, f);
}