bundle2: add a ``newpart`` method to ``bundle20`` Creating new parts is the most common operation people do when exposed to a bundler. We create a dedicated method on the bundler object for it. This will simplify the code and also avoid having to import the ``mercurial.bundle2`` module in multiple places. One part creators have been updated for testing purpose.

+
−try:
+
−    import coverage
+
−    getattr(coverage, 'process_startup', lambda: None)()
+
−except ImportError:
+
−    pass