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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 update_checksum(self, progress_callback=None, chunk_size=None, checksum_kwargs=None, **kwargs):
 """Update checksum based on file."""

        self.checksum = self.storage(**kwargs).checksum(
            progress_callback=progress_callback, chunk_size=chunk_size,
            **(checksum_kwargs or {}))