proc DUformatDUPystrObjectMethod(selfNoCast: PyObject;
                                 args: openArray[PyObject] = @[];
                                 kwargs: PyKwArgType = nil): PyObject {.cdecl,
    ...raises: [], tags: [RootEffect], forbids: [].}

proc formatValue(res: var string; self: PyStrObject;
                 format_spec: static[string] = "") {.
    ...raises: [FormatPyObjectError].}

proc formatValue(res: var string; self: PyStrObject; format_spec: string) {.
    ...raises: [FormatPyObjectError], tags: [RootEffect], forbids: [].}

template bindFormatValue(T, selfToNimType) {.dirty.}

template genFormat(T) {.dirty.}

template handleValueErrorAsPyFormatExc(body)

template implFormatValue(T, impl) {.dirty.}