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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 start(self, input_data=None):
 """ Calls Docker API to start the container. The container must be created at the first place to run. It waits for the container to complete, fetches both stdout and stderr logs and returns through the given streams. Parameters input_data Optional. Input data sent to the container through container's stdin. """


        if input_data:
            raise ValueError("Passing input through container's stdin is not supported")

        if not self.is_created():
            raise RuntimeError("Container does not exist. Cannot start this container")

        # Get the underlying container instance from Docker API
        real_container = self.docker_client.containers.get(self.id)

        # Start the container
        real_container.start()