Factory constructor for bucket object.

        .. note::
          This will not make an HTTP request; it simply instantiates
          a bucket object owned by this client.

        :type bucket_name: str
        :param bucket_name: The name of the bucket to be instantiated.

        :type user_project: str
        :param user_project: (Optional) the project ID to be billed for API
                             requests made via the bucket.

        :rtype: :class:`google.cloud.storage.bucket.Bucket`
        :returns: The bucket object created.

def bucket(self, bucket_name, user_project=None):
        """Factory constructor for bucket object.

        .. note::
          This will not make an HTTP request; it simply instantiates
          a bucket object owned by this client.

        :type bucket_name: str
        :param bucket_name: The name of the bucket to be instantiated.

        :type user_project: str
        :param user_project: (Optional) the project ID to be billed for API
                             requests made via the bucket.

        :rtype: :class:`google.cloud.storage.bucket.Bucket`
        :returns: The bucket object created.
        """
        return Bucket(client=self, name=bucket_name, user_project=user_project)