Method delete

/**
 * Delete a file
 *
 * @param   string    $filename   The file path to delete.
 * @param   resource  $context    A valid context resource (optional) created with stream_context_create.
 * @param   boolean   $usePrefix  Controls the use of a prefix (optional).
 * @param   boolean   $relative   Determines if the filename given is relative. Relative paths do not have JPATH_ROOT stripped.
 *
 * @return  mixed
 *
 * @since   1.7.0
 */
public function delete($filename, $context = null, $usePrefix = true, $relative = false)
{
    // Capture PHP errors
    $php_errormsg = '';
    $track_errors = ini_get('track_errors');
    ini_set('track_errors', true);
    $filename = $this->_getFilename($filename, 'w', $usePrefix, $relative);
    if ($context) {
        // Use the provided context
        $res = @unlink($filename, $context);
    } elseif ($this->context) {
        // Use the object's context
        $res = @unlink($filename, $this->context);
    } else {
        // Don't use any context
        $res = @unlink($filename);
    }
    if (!$res && $php_errormsg) {
        $this->setError($php_errormsg());
    }
    // Restore error tracking to what it was before.
    ini_set('track_errors', $track_errors);
    return $res;
}