def METHOD_NAME(font):
    """
    Return a dict { postscriptName: location } of all named instances in a given font.
    """
    instances = OrderedDict()
    if font is None:
        return instances
    fontDescriptor = font.fontDescriptor()
    url = CoreText.CTFontDescriptorCopyAttribute(fontDescriptor, CoreText.kCTFontURLAttribute)
    if url is None:
        return instances
    variationAxesDescriptions = CoreText.CTFontCopyVariationAxes(font)
    if variationAxesDescriptions is None:
        # non-variable fonts have no named instances
        return instances
    tagNameMap = {}
    for variationAxesDescription in variationAxesDescriptions:
        tag = convertIntToVariationTag(variationAxesDescription[CoreText.kCTFontVariationAxisIdentifierKey])
        name = variationAxesDescription[CoreText.kCTFontVariationAxisNameKey]
        tagNameMap[tag] = name
    ft = TTFont(url.path(), lazy=True, fontNumber=0)
    if "fvar" in ft:
        cgFont, _ = CoreText.CTFontCopyGraphicsFont(font, None)
        fvar = ft["fvar"]
        for instance in fvar.instances:
            fontVariations = dict()
            for axis, value in instance.coordinates.items():
                fontVariations[tagNameMap[axis]] = value
            varFont = CoreText.CGFontCreateCopyWithVariations(cgFont, fontVariations)
            postScriptName = CoreText.CGFontCopyPostScriptName(varFont)
            instances[postScriptName] = instance.coordinates
    ft.close()
    return instances