original_string: public function getId($alias)
      {
          if (!isset($this->aliases[$alias])) {
              return null;
          }
  
          $id = $this->aliases[$alias];
          while (isset($this->aliases[$id])) {
              $id = $this->aliases[$id];
          }
  
          return $id;
      }
code: public function getId($alias)
      {
          if (!isset($this->aliases[$alias])) {
              return null;
          }
  
          $id = $this->aliases[$alias];
          while (isset($this->aliases[$id])) {
              $id = $this->aliases[$id];
          }
  
          return $id;
      }
code_tokens: public function getId ( $ alias ) { if ( ! isset ( $ this -> aliases [ $ alias ] ) ) { return null ; } $ id = $ this -> aliases [ $ alias ] ; while ( isset ( $ this -> aliases [ $ id ] ) ) { $ id = $ this -> aliases [ $ id ] ; } return $ id ; }
docstring: Returns the identifier of the item which has the given alias
  
  @param string $alias The item alias
  
  @return string|null The item identifier or null if no one item has the given alias
docstring_tokens: Returns the identifier of the item which has the given alias