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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _sample_mvn(n_samples, cov, prng):
 """Draw a multivariate normal sample from the graph defined by cov. Parameters n_samples : int cov : matrix of shape (n_features, n_features) Covariance matrix of the graph. prng : np.random.RandomState instance. """

    n_features, _ = cov.shape
    return prng.multivariate_normal(np.zeros(n_features), cov, size=n_samples)