docs: def releases(self):
          r"""
          A dictionary that maps release identifiers to :class:`Release` objects.
  
          Here's an example based on a mirror of the git project's repository
          which shows the last ten releases based on tags, where each release
          identifier captures a tag without its 'v' prefix:
  
          >>> from pprint import pprint
          >>> from vcs_repo_mgr.backends.git import GitRepo
          >>> repository = GitRepo(remote='https://github.com/git/git.git',
          ...                      release_scheme='tags',
          ...                      release_filter=r'^v(\d+(?:\.\d+)*)$')
          >>> pprint(repository.ordered_releases[-10:])
          [Release(revision=Revision(..., tag='v2.2.2', ...), identifier='2.2.2'),
           Release(revision=Revision(..., tag='v2.3.0', ...), identifier='2.3.0'),
           Release(revision=Revision(..., tag='v2.3.1', ...), identifier='2.3.1'),
           Release(revision=Revision(..., tag='v2.3.2', ...), identifier='2.3.2'),
           Release(revision=Revision(..., tag='v2.3.3', ...), identifier='2.3.3'),
           Release(revision=Revision(..., tag='v2.3.4', ...), identifier='2.3.4'),
           Release(revision=Revision(..., tag='v2.3.5', ...), identifier='2.3.5'),
           Release(revision=Revision(..., tag='v2.3.6', ...), identifier='2.3.6'),
           Release(revision=Revision(..., tag='v2.3.7', ...), identifier='2.3.7'),
           Release(revision=Revision(..., tag='v2.4.0', ...), identifier='2.4.0')]
          """
          available_releases = {}
          available_revisions = getattr(self, self.release_scheme)
          for identifier, revision in available_revisions.items():
              match = self.compiled_filter.match(identifier)
              if match:
                  # If the regular expression contains a capturing group we
                  # set the release identifier to the captured substring
                  # instead of the complete tag/branch identifier.
                  captures = match.groups()
                  if captures:
                      identifier = captures[0]
                  available_releases[identifier] = Release(
                      revision=revision,
                      identifier=identifier,
                  )
          return available_releases