The following describes map options. Example:

  $default_map = array(
    'options' => array(
      'displayProjection' => '4326',
      'maxResolution' => 156543.0339,
      'maxExtent' => array(
        'left' => -20037508.34,
        'bottom' => -20037508.34,
        'right' => 20037508.34,
        'top' => 20037508.34,
      ),
      'fractionalZoom' => ??
    ),
  );