Convenience method to sample from this distribution.

        Args:
            size (int or tuple): Shape of return value. Each element is drawn
                independently from this distribution.

def rvs(self, size=1):
        """Convenience method to sample from this distribution.

        Args:
            size (int or tuple): Shape of return value. Each element is drawn
                independently from this distribution.

        """
        return np.random.multivariate_normal(self.mean, self.cov, size)