code: def multivariate_normal(random, mean, cov):
      
      from numpy.linalg import cholesky
  
      L = cholesky(cov)
      return L @ random.randn(L.shape[0]) + mean
docs: Draw random samples from a multivariate normal distribution.
  
      Parameters
      ----------
      random : np.random.RandomState instance
          Random state.
      mean : array_like
          Mean of the n-dimensional distribution.
      cov : array_like
          Covariance matrix of the distribution. It must be symmetric and
          positive-definite for proper sampling.
  
      Returns
      -------
      out : ndarray
          The drawn sample.