OpenDaylight "fails to fail" on mounting device which doens't provide schemas if there are other schemas in cache

There's a test in NetconfDeviceSchemaProviderFactory.java which (I believe) is intended to check if a device has not provided any schemas:

Preconditions.checkState(sourceContext.getValidSources().isEmpty() == false,
"%s: Unable to create schema context, no sources provided by device", id);

however this check only fails if the ~/cache/schema directory is completely empty. If there are files in the directory which were provided by another device then the check "fails to fail" and the device is mounted despite failing to provide any sources.

Is this intentional?