SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function mapSort (children 1)
     ExpressionList (children 2)
      Function lambda (children 1)
       ExpressionList (children 2)
        Function tuple (children 1)
         ExpressionList (children 2)
          Identifier k
          Identifier v
        Identifier k
      Function map (children 1)
       ExpressionList (children 4)
        Function tuple (children 1)
         ExpressionList (children 2)
          Literal UInt64_1
          Literal UInt64_2
        Literal UInt64_4
        Function tuple (children 1)
         ExpressionList (children 2)
          Literal UInt64_3
          Literal UInt64_4
        Literal UInt64_5