gistfile1.php

<?php  

protected function supportedInterfaceOrClass($data, $format = NULL) {
    // If there is a format passed in and specified on the class, check if it is
    // correct.
    if (isset($format) && isset($this->format) && !in_array($format, $this->format)) {
      return FALSE;
    }

    if (is_object($data)) {
      foreach ((array) $this->supportedInterfaceOrClass as $name) {
        if ($data instanceof $name) {
          return TRUE;
        }
      }
    }
    else {
      $reflection = new ReflectionClass($type);
      foreach ((array) $this->supportedInterfaceOrClass as $name) {
        if ($reflection->implementsInterface($this->supportedInterfaceOrClass)) {
          return TRUE;
        }
      }
    }

    return FALSE;
  }