test: mark some uncovered lines in collector.py
test: mark some uncovered lines in collector.py

hugovk/coveragepy,hugovk/coveragepy,nedbat/coveragepy,hugovk/coveragepy,nedbat/coveragepy,nedbat/coveragepy,nedbat/coveragepy,nedbat/coveragepy,hugovk/coveragepy,hugovk/coveragepy