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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 contrib_setup_py(name, description, additional_classifiers=None, **kwargs):
 """Creates the setup_py for a pants contrib plugin artifact. :param str name: The name of the package; must start with 'pantsbuild.pants.contrib.'. :param str description: A brief description of what the plugin provides. :param list additional_classifiers: Any additional trove classifiers that apply to the plugin, see: https://pypi.org/pypi?%3Aaction=list_classifiers :param kwargs: Any additional keyword arguments to be passed to `setuptools.setup <https://pythonhosted.org/setuptools/setuptools.html>`_. :returns: A setup_py suitable for building and publishing pants components. """

  if not name.startswith('pantsbuild.pants.contrib.'):
    raise ValueError("Contrib plugin package names must start with 'pantsbuild.pants.contrib.', "
                     "given {}".format(name))

  return pants_setup_py(name,
                        description,
                        additional_classifiers=additional_classifiers,
                        namespace_packages=['pants', 'pants.contrib'],
                        **kwargs)