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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 size(self):
 """Bytes uploaded of the file so far. Note that we only have the file size if the file was requested directly, not if it's part of a folder listing. """

        if hasattr(self.f.latestRevision, 'size'):
            return int(self.f.latestRevision.size)
        return None