public function getAliases($extension = null)
    {
        if ($extension === null) {
            return $this->aliases;
        }
        elseif (isset($this->aliases[$extension])) {
            return $this->aliases[$extension];
        }
        else {
            return null;
        }
    }
public function getAliases($extension = null)
    {
        if ($extension === null) {
            return $this->aliases;
        }
        elseif (isset($this->aliases[$extension])) {
            return $this->aliases[$extension];
        }
        else {
            return null;
        }
    }
public function getAliases ( $ extension = null ) { if ( $ extension === null ) { return $ this -> aliases ; } elseif ( isset ( $ this -> aliases [ $ extension ] ) ) { return $ this -> aliases [ $ extension ] ; } else { return null ; } }
Returns aliases.
@param string $extension Extension name. Eg: css
@return self
Returns aliases .