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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_client_by_id(self, client_id):
 """Get GRR client dictionary and make sure valid approvals exist. Args: client_id: GRR client ID. Returns: GRR API Client object """

    client = self.grr_api.Client(client_id)
    print('Checking for client approval')
    self._check_approval_wrapper(client, client.ListFlows)
    print('{0:s}: Client approval is valid'.format(client_id))
    return client.Get()