code: public static function get($strKey)
  	{
  		if (isset(static::$arrCache[$strKey]))
  		{
  			return static::$arrCache[$strKey];
  		}
  
  		if (\in_array($strKey, get_class_methods(__CLASS__)))
  		{
  			static::$arrCache[$strKey] = static::$strKey();
  		}
  		else
  		{
  			$arrChunks = preg_split('/([A-Z][a-z]*)/', $strKey, -1, PREG_SPLIT_DELIM_CAPTURE|PREG_SPLIT_NO_EMPTY);
  			$strServerKey = strtoupper(implode('_', $arrChunks));
  			static::$arrCache[$strKey] = $_SERVER[$strServerKey];
  		}
  
  		return static::$arrCache[$strKey];
  	}
docs: Return an environment variable
  
  @param string $strKey The variable name
  
  @return mixed The variable value