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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 _ProcessRegistryKeySource(self, source):
 """Glob for paths in the registry."""

    keys = source.base_source.attributes.get("keys", [])
    if not keys:
      return

    interpolated_paths = artifact_utils.InterpolateListKbAttributes(
        input_list=keys,
        knowledge_base=self.knowledge_base,
        ignore_errors=self.ignore_interpolation_errors)

    glob_expressions = map(rdf_paths.GlobExpression, interpolated_paths)

    patterns = []
    for pattern in glob_expressions:
      patterns.extend(pattern.Interpolate(knowledge_base=self.knowledge_base))
    patterns.sort(key=len, reverse=True)

    file_finder_action = rdf_file_finder.FileFinderAction.Stat()
    request = rdf_file_finder.FileFinderArgs(
        paths=patterns,
        action=file_finder_action,
        follow_links=True,
        pathtype=rdf_paths.PathSpec.PathType.REGISTRY)
    action = vfs_file_finder.RegistryKeyFromClient

    yield action, request