def METHOD_NAME():
    usage = "pyFAI-drawmask file1.edf file2.edf ..."
    version = "pyFAI-average version %s from %s" % (pyFAI.version, pyFAI.date)
    description = """
    Draw a mask, i.e. an image containing the list of pixels which are considered invalid
    (no scintillator, module gap, beam stop shadow, ...).
    This will open a window and let you draw on the first image
    (provided) with different tools (brush, rectangle selection...)
    When you are finished, click on the "Save and quit" button.
    """
    epilog = """The mask image is saved into file1-masked.edf.
    Optionally the script will print the number of pixel masked
    and the intensity masked (as well on other files provided in input)"""
    parser = ArgumentParser(usage=usage, description=description, epilog=epilog)
    parser.add_argument("-v", "--version", action='version', version=version)
    parser.add_argument("args", metavar='FILE', type=str, nargs='+',
                        help="Files to be processed")
    options = parser.parse_args()
    if len(options.args) < 1:
        parser.error("Incorrect number of arguments: please provide an image to draw a mask")
    processFile = pyFAI.utils.expand_args(options.args)
    app = qt.QApplication([])
    window = MaskImageWidget()
    image = fabio.open(processFile[0]).data
    window.setImageData(image)
    window.show()
    outfile = os.path.splitext(processFile[0])[0] + "-mask.edf"
    window.setOutputFile(outfile)
    print("Your mask-file will be saved into %s" % (outfile))
    app.exec_()
    mask = window.getSelectionMask()
    postProcessId21(processFile, mask)