code: def unitcube_overlap(self, ndraws=10000, rstate=None):
          
  
          if rstate is None:
              rstate = np.random
  
          samples = [self.sample(rstate=rstate) for i in range(ndraws)]
          nin = sum([unitcheck(x) for x in samples])
  
          return 1. * nin / ndraws
docs: Using `ndraws` Monte Carlo draws, estimate the fraction of
          overlap between the ellipsoid and the unit cube.