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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 get_supported_types(resource_root, category_name):
 """ Lookup all supported types in a category. @param resource_root: The root Resource object. @param category_name: The category name @return: An ApiExternalAcccountType list """

  return call(resource_root.get,
      EXTERNAL_ACCOUNT_FETCH_PATH % ("supportedTypes", category_name,),
      ApiExternalAccountType, True)