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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_function_policy(self, function_name):
 # type: (str) -> Dict[str, Any] """Return the function policy for a lambda function. This function will extract the policy string as a json document """

        client = self._client('lambda')
        try:
            policy = client.get_policy(FunctionName=function_name)
            return json.loads(policy['Policy'])
        except client.exceptions.ResourceNotFoundException:
            return {'Statement': []}