SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Function isNull (children 1)
     ExpressionList (children 1)
      Identifier one
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier one_table
   Function isNull (children 1)
    ExpressionList (children 1)
     Identifier one
