def METHOD_NAME(X, Y):
    """
    Indices of elements in a numpy array that appear in another.
    Fast routine for determining indices of elements in numpy array `X` that
    appear in numpy array `Y`, returning a boolean array `Z` such that::
            Z[i] = X[i] in Y
    """
    if len(Y) > 0:
        T = Y.copy()
        T.sort()
        D = T.searchsorted(X)
        T = np.append(T, np.array([0]))
        W = T[D] == X
        if isinstance(W, bool):
            return np.zeros((len(X),), bool)
        else:
            return T[D] == X
    else:
        return np.zeros((len(X),), bool)