SimplePie::get_description

	 * @since 1.1
	 * @return array|null List of {@see SimplePie_Author} objects
	 */
	public function get_contributors()
	{
		$contributors = array();
		foreach ((array) $this->get_channel_tags(SIMPLEPIE_NAMESPACE_ATOM_10, 'contributor') as $contributor)
		{
			$name = null;
			$uri = null;
			$email = null;
			if (isset($contributor['child'][SIMPLEPIE_NAMESPACE_ATOM_10]['name'][0]['data']))
			{
				$name = $this->sanitize($contributor['child'][SIMPLEPIE_NAMESPACE_ATOM_10]['name'][0]['data'], SIMPLEPIE_CONSTRUCT_TEXT);
			}
			if (isset($contributor['child'][SIMPLEPIE_NAMESPACE_ATOM_10]['uri'][0]['data']))
			{
				$uri = $this->sanitize($contributor['child'][SIMPLEPIE_NAMESPACE_ATOM_10]['uri'][0]['data'], SIMPLEPIE_CONSTRUCT_IRI, $this->get_base($contributor['child'][SIMPLEPIE_NAMESPACE_ATOM_10]['uri'][0]));
			}
			if (isset($contributor['child'][SIMPLEPIE_NAMESPACE_ATOM_10]['email'][0]['data']))
			{
				$email = $this->sanitize($contributor['child'][SIMPLEPIE_NAMESPACE_ATOM_10]['email'][0]['data'], SIMPLEPIE_CONSTRUCT_TEXT);
			}
			if ($name !== null || $email !== null || $uri !== null)
			{
				$contributors[] = $this->registry->create('Author', array($name, $uri, $email));
			}
		}
		foreach ((array) $this->get_channel_tags(SIMPLEPIE_NAMESPACE_ATOM_03, 'contributor') as $contributor)
		{
			$name = null;
			$url = null;
			$email = null;
			if (isset($contributor['child'][SIMPLEPIE_NAMESPACE_ATOM_03]['name'][0]['data']))
			{
				$name = $this->sanitize($contributor['child'][SIMPLEPIE_NAMESPACE_ATOM_03]['name'][0]['data'], SIMPLEPIE_CONSTRUCT_TEXT);
			}
			if (isset($contributor['child'][SIMPLEPIE_NAMESPACE_ATOM_03]['url'][0]['data']))
			{
				$url = $this->sanitize($contributor['child'][SIMPLEPIE_NAMESPACE_ATOM_03]['url'][0]['data'], SIMPLEPIE_CONSTRUCT_IRI, $this->get_base($contributor['child'][SIMPLEPIE_NAMESPACE_ATOM_03]['url'][0]));
			}
			if (isset($contributor['child'][SIMPLEPIE_NAMESPACE_ATOM_03]['email'][0]['data']))
			{