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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_all_roles(resource_root, service_name, cluster_name="default", view=None):
 """ Get all roles @param resource_root: The root Resource object. @param service_name: Service name @param cluster_name: Cluster name @return: A list of ApiRole objects. """

  return call(resource_root.get,
      _get_roles_path(cluster_name, service_name),
      ApiRole, True, params=view and dict(view=view) or None)