code: def Poisson(lamda, tag=None):
      
      assert lamda > 0, 'Poisson "lamda" must be greater than zero.'
      return uv(ss.poisson(lamda), tag=tag)
docs: A Poisson random variate
      
      Parameters
      ----------
      lamda : scalar
          The rate of an occurance within a specified interval of time or space.