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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 _read_json_binary_field(deserialized, field):
    ''' Read the value of a JSON field that may be string or base64-encoded.
    '''
    val = deserialized.get(field)
    if val is not None:
        return utils.convert_to_bytes(val)
    val = deserialized.get(field + '64')
    if val is None:
        return None
    return utils.raw_urlsafe_b64decode(val)