Function deeply gets the key with "." notation

        Args
        ----
          key (string): A key with the "." notation.

        Returns
        -------
          reg (unknown type): Returns a dict or a primitive
            type.

def get(self, key):
        """
        Function deeply gets the key with "." notation

        Args
        ----
          key (string): A key with the "." notation.

        Returns
        -------
          reg (unknown type): Returns a dict or a primitive
            type.
        """
        try:
            layers = key.split('.')
            value = self.registrar
            for key in layers:
                value = value[key]
            return value
        except:
            return None