original_string: protected function _overwrite(&$old, $new)
      {
          if (!empty($old)) {
              foreach ($old as $key => $var) {
                  if (!isset($new[$key])) {
                      unset($old[$key]);
                  }
              }
          }
          foreach ($new as $key => $var) {
              $old[$key] = $var;
          }
      }
code: protected function _overwrite(&$old, $new)
      {
          if (!empty($old)) {
              foreach ($old as $key => $var) {
                  if (!isset($new[$key])) {
                      unset($old[$key]);
                  }
              }
          }
          foreach ($new as $key => $var) {
              $old[$key] = $var;
          }
      }
code_tokens: protected function _overwrite ( & $ old , $ new ) { if ( ! empty ( $ old ) ) { foreach ( $ old as $ key => $ var ) { if ( ! isset ( $ new [ $ key ] ) ) { unset ( $ old [ $ key ] ) ; } } } foreach ( $ new as $ key => $ var ) { $ old [ $ key ] = $ var ; } }
docstring: Used to write new data to _SESSION, since PHP doesn't like us setting the _SESSION var itself.
  
  @param array $old Set of old variables => values
  @param array $new New set of variable => value
  @return void
docstring_tokens: Used to write new data to _SESSION since PHP doesn t like us setting the _SESSION var itself .