def test_type(self):
        rset = event.ResultSet()
        with pytest.raises(NotImplementedError):
            rset.extend([])
        with pytest.raises(NotImplementedError):
            rset.extend(False)
def __init__(self, data, amount_clusters, means=None, variances=None, observer=None, tolerance=0.00001, iterations=100):
        """!
        @brief Initializes Expectation-Maximization algorithm for cluster analysis.