def METHOD_NAME():
    """Test that a constant input produces no outliers and that warnings are raised"""
    V = np.zeros(20)  # this will trigger a runtime warning
    with pytest.warns(RuntimeWarning):
        outliers = cleansing.detect_outliers(V, 1)
    assert outliers.size == V.shape[0]
    assert outliers.sum() == 0
    V = np.zeros((20, 3))  # this will trigger a singular matrix warning
    with pytest.warns(UserWarning):
        outliers = cleansing.detect_outliers(V, 1)
    assert outliers.size == V.shape[0]
    assert outliers.sum() == 0
    V = np.zeros((20, 3))  # this will trigger a singular matrix warning
    X = np.random.randint(100, size=(20, 3))
    with pytest.warns(UserWarning):
        outliers = cleansing.detect_outliers(V, 1, coord=X, k=10)
    assert outliers.size == V.shape[0]
    assert outliers.sum() == 0