/**
  * parse method
  *
  * Parse given timestamp into I18n date/time values map.
  *
  * @param int  $timestamp Timestamp to parse
  * @param bool $is_gmt    Set to true, to treat value as present in GMT
  *
  * @return array Map of date format keys and corresponding time values
  */
 public function parse($timestamp = false, $is_gmt = false)
 {
     $timestamp = Ai1ec_Time_Utility::normalize_timestamp($timestamp, $is_gmt);
     $cache_key = $timestamp . "" . $is_gmt;
     if (NULL === ($record = $this->_memory->get($cache_key))) {
         $record = array_combine($this->_keys, explode($this->_separator, date_i18n($this->_format, $timestamp, $is_gmt)));
         $this->_memory->set($cache_key, $record);
     }
     return $record;
 }