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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 _query(self, filename):
 """Get size of filename"""

        #  - Query metadata of one file
        #  - Return a dict with a 'size' key, and a file size value (-1 for not found)
        #  - Retried if an exception is thrown
        log.Info('Querying size of %s' % filename)
        from jottalib.JFS import JFSNotFoundError, JFSIncompleteFile
        remote_path = posixpath.join(self.folder.path, filename)
        try:
            remote_file = self.client.getObject(remote_path)
        except JFSNotFoundError:
            return {'size': -1}
        return {
            'size': remote_file.size,
        }