Method render

/**
 * Renders the document head and returns the results as a string
 *
 * @param   string  $head     (unused)
 * @param   array   $params   Associative array of values
 * @param   string  $content  The script
 *
 * @return  string  The output of the script
 *
 * @since   3.5
 */
public function render($head, $params = array(), $content = null)
{
    $buffer = '';
    $buffer .= $this->_doc->loadRenderer('metas')->render($head, $params, $content);
    $buffer .= $this->_doc->loadRenderer('styles')->render($head, $params, $content);
    $buffer .= $this->_doc->loadRenderer('scripts')->render($head, $params, $content);
    return $buffer;
}