in spotify_confidence/analysis/frequentist/sequential_bound_solver.py [0:0]
def __init__(self, df: pandas.DataFrame, last_fcab: np.array):
if df is None or any(df["zb"].isnull()) or len(df) > 0 and last_fcab is None:
raise ValueError()
self._df = df
self._last_fcab = last_fcab