code: def sample_normal(mean, var, rng):
      
      ret = numpy.sqrt(var) * rng.randn(*mean.shape) + mean
      return ret
docs: Sample from independent normal distributions
  
      Each element is an independent normal distribution.
  
      Parameters
      ----------
      mean : numpy.ndarray
        Means of the normal distribution. Shape --> (batch_num, sample_dim)
      var : numpy.ndarray
        Variance of the normal distribution. Shape --> (batch_num, sample_dim)
      rng : numpy.random.RandomState
  
      Returns
      -------
      ret : numpy.ndarray
         The sampling result. Shape --> (batch_num, sample_dim)