def manage_sheep(self, identity, environment):

		if identity in self._flock:
			return False

		if not isinstance(environment, dict):
			raise TypeError("environment must be a dict.")

		self._flock[identity] = FlockManager.SheepInfo(environment, None)

		self.sheep_bleeted(identity)

		return True
Tell the flock manager to keep track of the given sheep. Returns True if
dataset/ETHPy150Open ucrcsedept/galah/galah/shepherd/flockmanager.py/FlockManager.manage_sheep