def METHOD_NAME(self, annotation_file):
    labels, x_mins, y_mins, x_maxs, y_maxs = [], [], [], [], []
    for line in read_txt(self.annotation_dir / annotation_file):
        label, x_min, y_min, x_max, y_max = line.split()
        labels.append(int(label) + self.shift_labels)
        x_mins.append(float(x_min))
        y_mins.append(float(y_min))
        x_maxs.append(float(x_max))
        y_maxs.append(float(y_max))
    return np.array(labels), np.array(x_mins), np.array(y_mins), np.array(x_maxs), np.array(y_maxs)