SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function toTypeName (children 1)
     ExpressionList (children 1)
      Function getSubcolumn (children 1)
       ExpressionList (children 2)
        Function CAST (children 1)
         ExpressionList (children 2)
          Function tuple (children 1)
           ExpressionList (children 1)
            Literal \'str\'
          Literal \'Tuple(a LowCardinality(String))\'
        Literal \'a\'
