def getPrimes(self):
        """
        Called when the factory is started to get Diffie-Hellman generators and
        primes to use.  Returns a dictionary mapping number of bits to lists
        of tuple of (generator, prime).

        @rtype: L{dict}
        """

        Called when the factory is started to get Diffie-Hellman generators and
        primes to use.  Returns a dictionary mapping number of bits to lists
        of tuple of (generator, prime).

        @rtype: L{dict}
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/conch/ssh/factory.py