code: func WBBKeyGen(rng *amcl.RAND) (*FP256BN.BIG, *FP256BN.ECP2) {
  	// sample sk uniform from Zq
  	sk := RandModOrder(rng)
  	// set pk = g2^sk
  	pk := GenG2.Mul(sk)
  	return sk, pk
  }
docs: // WBBKeyGen creates a fresh weak-Boneh-Boyen signature key pair (http://ia.cr/2004/171)