Get the string representation of the object stored in DynamoDB under this key,
        convert it back to an object using the 'from_string' unmarshalling method passed
        in the constructor and return the object. Return None if no object found.

def get(self, key):
        """Get the string representation of the object stored in DynamoDB under this key,
        convert it back to an object using the 'from_string' unmarshalling method passed
        in the constructor and return the object. Return None if no object found.
        """
        self._get_table()
        s = self.table.get_item(key=key)
        log.debug("Retrieved from key '%s' the object: '%s'" % (key, s['value']))
        return self.from_string(s['value'])