def METHOD_NAME(ds):
    t1 = ds.get_t1df()
    t1.reset_index(inplace=True)
    # key = "/ORSIS3302DecoderForEnergy"
    # wf_chunk = pd.read_hdf(t1, key, where="ievt < {}".format(75000))
    # key = "/ORSIS3302DecoderForEnergy"
    icols = []
    for idx, col in enumerate(t1.columns):
        if isinstance(col, int):
            icols.append(col)
    wfs = t1[icols].values
    wfs = wfs[:20000]
    # xvals = np.arange(0,3000)
    # start = time.time()
    # for i in range(0,5):
    # # for i in range(0,5):
    #     plt.plot(xvals, wfs[i], lw=1)
    #     plt.xlabel('Sample Number', ha='right', x=1.0)
    #     plt.ylabel('ADC Value', ha='right', y=1.0)
    #     plt.tight_layout()
    #     plt.show()