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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def generate_control_field(self, revision=None):
 """ Generate a Debian control file field referring for this repository and revision. :param revision: A reference to a revision, most likely the name of a branch (a string, defaults to :attr:`default_revision`). :returns: A tuple with two strings: The name of the field and the value. This generates a `Vcs-Bzr` field for Bazaar repositories, a `Vcs-Git` field for Git repositories and a `Vcs-Hg` field for Mercurial repositories. Here's an example based on the public git repository of the `vcs-repo-mgr` project: ('Vcs-Git', 'https://github.com/xolox/python-vcs-repo-mgr.git#b617731b6c0ca746665f597d2f24b8814b137ebc') """

        value = "%s#%s" % (self.remote or self.local, self.find_revision_id(revision))
        return self.control_field, value