SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 2)
    Function mapAdd (alias res) (children 1)
     ExpressionList (children 2)
      Function tuple (children 1)
       ExpressionList (children 2)
        Function CAST (children 1)
         ExpressionList (children 2)
          Literal Array_[\'a\', \'b\']
          Literal \'Array(FixedString(1))\'
        Literal Array_[UInt64_1, UInt64_1]
      Function tuple (children 1)
       ExpressionList (children 2)
        Function array (children 1)
         ExpressionList (children 1)
          Identifier key
        Literal Array_[UInt64_1]
    Function toTypeName (children 1)
     ExpressionList (children 1)
      Identifier res
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Function values (children 1)
       ExpressionList (children 4)
        Literal \'key FixedString(1)\'
        Literal \'b\'
        Literal \'c\'
        Literal \'d\'
