'Generate a list of the content of all blobs that can be reached
from an object.  The hash given in \'id\' must point to a blob, a tree
or a commit. The content of all blobs that can be seen from trees or
commits will be added to the list.'

def join(self, id):

    try:
        for d in self._join(self.get(id)):
            (yield d)
    except StopIteration:
        log('booger!\n')
