DescribeQuery (children 1)
 TableExpression (children 1)
  Subquery (children 1)
   SelectWithUnionQuery (children 1)
    ExpressionList (children 1)
     SelectQuery (children 2)
      ExpressionList (children 3)
       Function CAST (alias a) (children 1)
        ExpressionList (children 2)
         Function tuple (children 1)
          ExpressionList (children 1)
           Literal UInt64_1
         Literal \'Tuple (id UInt64)\'
       Function untuple (alias untupled_value) (children 1)
        ExpressionList (children 1)
         Identifier a
       Function arrayMap (children 1)
        ExpressionList (children 2)
         Function lambda (children 1)
          ExpressionList (children 2)
           Function tuple (children 1)
            ExpressionList (children 1)
             Identifier x
           Identifier untupled_value
         Literal Array_[UInt64_1, UInt64_2, UInt64_3]
      TablesInSelectQuery (children 1)
       TablesInSelectQueryElement (children 1)
        TableExpression (children 1)
         TableIdentifier test_table