human
Complete the below
def addUnitTypeConversion(unitLabel, mappingFunc):

    ''''Add support for converting units specified by unit_label to pixels
    to be used by convertToPix (therefore a valid unit for your PsychoPy
    stimuli)
    mapping_func must have the function prototype:
    def mapping_func(vertices, pos, win):
    # Convert the input vertices, pos to pixel positions PsychoPy
    # will use for OpenGL call.
    # unit type -> pixel mapping logic here
    return pix'
    '''
 ... Give me a the Python program you requested?
assistant
#Here is the Python program you requested.
    if (unitLabel in _unit2PixMappings):
        msg = 'The    unit    type    label    [{0}]    is    already    registered    with    PsychoPy'
        raise ValueError(msg.format(unitLabel))
    _unit2PixMappings[unitLabel] = mappingFunc