Function batch_encode_numpy 

pub(crate) fn batch_encode_numpy<'py>(
    py: Python<'py>,
    probs: PyReadonlyArray1<'py, f64>,
    length: usize,
    seed: u64,
) -> PyResult<Bound<'py, PyArray2<u64>>>

Bernoulli-encode a numpy float64 array into a 2-D numpy uint64 array.

Returns shape (n_probs, ceil(length / 64)).