src/Zend/Loader/Autoloader.php
protected function _autoload($class)
    {
        $callback = $this->getDefaultAutoloader();
        try {
            if ($this->suppressNotFoundWarnings()) {
                @call_user_func($callback, $class);
            } else {
                call_user_func($callback, $class);
            }
            return $class;
        } catch (Zend_Exception $e) {
            return false;
        }
    }
protected function _autoload($class)
    {
        $callback = $this->getDefaultAutoloader();
        try {
            if ($this->suppressNotFoundWarnings()) {
                @call_user_func($callback, $class);
            } else {
                call_user_func($callback, $class);
            }
            return $class;
        } catch (Zend_Exception $e) {
            return false;
        }
    }
protected function _autoload ( $ class ) { $ callback = $ this -> getDefaultAutoloader ( ) ; try { if ( $ this -> suppressNotFoundWarnings ( ) ) { @ call_user_func ( $ callback , $ class ) ; } else { call_user_func ( $ callback , $ class ) ; } return $ class ; } catch ( Zend_Exception $ e ) { return false ; } }
Internal autoloader implementation

@param  string $class
@return bool
Internal autoloader implementation