def sample(self):
        """
        Returns:
            A PyTorch Tensor of samples from the diagonal Gaussian distribution with
            mean and log_std given by self.mu and self.log_std.
        """
        #######################
        #                     #
        #   YOUR CODE HERE    #
        #                     #
        #######################
        pass

        Returns:
            A PyTorch Tensor of samples from the diagonal Gaussian distribution with
            mean and log_std given by self.mu and self.log_std.
        
spinup/exercises/pytorch/problem_set_1/exercise1_2.py