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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 get_by_id(self, institution_id, _options=None):
        '''
        Fetch a single institution by id.

        :param  str     institution_id:
        '''
        options = _options or {}

        return self.client.post_public_key('/institutions/get_by_id', {
            'institution_id': institution_id,
            'options': options,
        })