protected static function _log($mValue, $sFilePath = null)
{
static $_fPreviousTimeStamp = 0;
$_oCallerInfo = debug_backtrace();
$_sCallerFunction = self::_getCallerFunctionName($_oCallerInfo);
$_sCallerClass = self::_getCallerClassName($_oCallerInfo);
$_fCurrentTimeStamp = microtime(true);
file_put_contents(self::_getLogFilePath($sFilePath, $_sCallerClass), self::_getLogContents($mValue, $_fCurrentTimeStamp, $_fPreviousTimeStamp, $_sCallerClass, $_sCallerFunction), FILE_APPEND);
$_fPreviousTimeStamp = $_fCurrentTimeStamp;
}