SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function map (alias m) (children 1)
     ExpressionList (children 4)
      Literal \'1\'
      Literal UInt64_2
      Literal \'3\'
      Literal UInt64_4
   ExpressionList (children 1)
    Function arrayElementOrNull (children 1)
     ExpressionList (children 2)
      Identifier m
      Literal \'3\'
