Allow to specify specific threshold to jitter function.

    print("Outliers:", len(outliers), ";", "Threshold[us]:", threshold)

def trace_jitter(data_frame, export=False, file_name=None):

def trace_jitter(data_frame, threshold=None, export=False, file_name=None):

    """

    Displays (and saves) a stacked boxplot of durations.

    """

    thresh = get_outlier_threshold(data_frame["EndToEnd_D"].describe())

    df_no_outliers = data_frame[data_frame["EndToEnd_D"] <= thresh]

    if threshold is None:

        threshold = get_outlier_threshold(data_frame["EndToEnd_D"].describe())

    df_no_outliers = data_frame[data_frame["EndToEnd_D"] <= threshold]

    box(df_no_outliers, export, file_name)

    print("{} / {} are no outliers.".format(len(df_no_outliers), len(data_frame)))

    fig = plt.gcf()