Clarify how TreeMatcher works.
Clarify how TreeMatcher works.

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