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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 shade_package(cls, package_name=None, recursive=False):
 """Includes the given fully qualified package name in shading. :param unicode package_name: A fully qualified package_name; eg: `org.pantsbuild`; `None` for the java default (root) package. :param bool recursive: `True` to include any package with `package_name` as a proper prefix; `False` by default. :returns: A `Shader.Rule` describing the packages to be shaded. """

    if not package_name:
      return Shading.create_relocate('**' if recursive else '*')
    return Shading.create_relocate_package(package_name, recursive=recursive)