<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def ensure_resampled_obs_ids_in_df(resampled_obs_ids, orig_obs_id_array):
 """ Checks whether all ids in `resampled_obs_ids` are in `orig_obs_id_array`. Raises a helpful ValueError if not. Parameters resampled_obs_ids : 1D ndarray of ints. Should contain the observation ids of the observational units that will be used in the current bootstrap sample. orig_obs_id_array : 1D ndarray of ints. Should countain the observation ids of the observational units in the original dataframe containing the data for this model. Returns ------- None. """

    if not np.in1d(resampled_obs_ids, orig_obs_id_array).all():
        msg =\
            "All values in `resampled_obs_ids` MUST be in `orig_obs_id_array`."
        raise ValueError(msg)
    return None