* @param string $package name of the package this error stack represents
* @param callback $msgCallback callback used for error message generation
* @param callback $contextCallback callback used for context generation,
* defaults to {@link getFileLine()}
* @param boolean $throwPEAR_Error
*/
* @param string $package name of the package this error stack represents
* @param callback $msgCallback callback used for error message generation
* @param callback $contextCallback callback used for context generation,
* defaults to {@link getFileLine()}
* @param boolean $throwPEAR_Error
*/