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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 RunPlugins( cls, artifacts_registry, file_system, mount_point, knowledge_base):
 """Runs the preprocessing plugins. Args: artifacts_registry (artifacts.ArtifactDefinitionsRegistry):
 artifacts definitions registry. file_system (dfvfs.FileSystem):
 file system to be preprocessed. mount_point (dfvfs.PathSpec):
 mount point path specification that refers to the base location of the file system. knowledge_base (KnowledgeBase):
 to fill with preprocessing information. """

    searcher = file_system_searcher.FileSystemSearcher(file_system, mount_point)

    cls.CollectFromFileSystem(
        artifacts_registry, knowledge_base, searcher, file_system)

    # Run the Registry plugins separately so we do not have to open
    # Registry files for every preprocess plugin.

    environment_variables = None
    if knowledge_base:
      environment_variables = knowledge_base.GetEnvironmentVariables()

    registry_file_reader = FileSystemWinRegistryFileReader(
        file_system, mount_point, environment_variables=environment_variables)
    win_registry = dfwinreg_registry.WinRegistry(
        registry_file_reader=registry_file_reader)

    searcher = registry_searcher.WinRegistrySearcher(win_registry)

    cls.CollectFromWindowsRegistry(
        artifacts_registry, knowledge_base, searcher)

    cls.CollectFromKnowledgeBase(knowledge_base)

    if not knowledge_base.HasUserAccounts():
      logger.warning('Unable to find any user accounts on the system.')