<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def was_active(reference_date_value, asset):
 """ Whether or not `asset` was active at the time corresponding to `reference_date_value`. Parameters reference_date_value : int Date, represented as nanoseconds since EPOCH, for which we want to know if `asset` was alive. This is generally the result of accessing the `value` attribute of a pandas Timestamp. asset : Asset The asset object to check. Returns ------- was_active : bool Whether or not the `asset` existed at the specified time. """

    return (
        asset.start_date.value
        <= reference_date_value
        <= asset.end_date.value
    )