SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 1) ExpressionList (children 1) Function mapConcat (children 1) ExpressionList (children 2) Literal Array_[UInt64_1, UInt64_2] Function map (children 1) ExpressionList (children 2) Literal UInt64_1 Literal UInt64_2