SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 2)
    Function mapFromArrays (alias x) (children 1)
     ExpressionList (children 2)
      Literal Array_[UInt64_1, UInt64_2]
      Literal Array_[UInt64_3, UInt64_4]
    Function mapFromArrays (children 1)
     ExpressionList (children 2)
      Identifier x
      Literal Array_[\'a\', \'b\']