def METHOD_NAME(i, hz, test_pulse=True):
    """
    Find index range for the experiment epoch.
    The start index of the experiment epoch is defined as stim_start_idx - PRESTIM_DURATION*sampling_rate
    The end index of the experiment epoch is defined as stim_end_idx + POSTSTIM_DURATION*sampling_rate
    Parameters
    ----------
    i   :   float np.array of current
    hz  :   float sampling rate
    test_pulse: bool True if present, False otherwise
    Returns
    -------
    (expt_start_idx,expt_end_idx): int tuple with start, end indices of the epoch
    """
    stim_epoch = get_stim_epoch(i,test_pulse)
    if stim_epoch:
        stim_start_idx,stim_end_idx = stim_epoch
        expt_start_idx = stim_start_idx - int(PRESTIM_STABILITY_EPOCH * hz)
        expt_end_idx = stim_end_idx + int(POSTSTIM_STABILITY_EPOCH * hz)
        return expt_start_idx,expt_end_idx
    else:
        return None