5.3.5 ProtocolsPerHandle()

This service retrieves the list of protocols that are installed on a handle. In general, UEFI drivers know what protocols are installed on the handles that the UEFI driver is managing, so this service is not required for proper UEFI Driver operation. This service is typically used by UEFI applications, such as diagnostics or debug utilities, that need to traverse the entire contents of the Handle Database.