SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Identifier id
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier tab
   Function hasAnyTokens (children 1)
    ExpressionList (children 2)
     Identifier message
     Function materialize (children 1)
      ExpressionList (children 1)
       Literal \'b\'
