SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function tupleConcat (children 1)
     ExpressionList (children 2)
      Literal Tuple_(UInt64_1, \'y\')
      Literal Tuple_(UInt64_2, \'n\')
