def suffixed_err(src: str, pos: Pos, msg: str) -> TOMLDecodeError:
    """Return a `TOMLDecodeError` where error message is suffixed with
    coordinates in source."""

    def coord_repr(src: str, pos: Pos) -> str:
        if pos >= len(src):
            return "end of document"
        line = src.count("\n", 0, pos) + 1
        if line == 1:
            column = pos + 1
        else:
            column = pos - src.rindex("\n", 0, pos)
        return f"line {line}, column {column}"

    return TOMLDecodeError(f"{msg} (at {coord_repr(src, pos)})")
Return a `TOMLDecodeError` where error message is suffixed with
    coordinates in source.
product/gradle-plugin/src/main/python/pip/_vendor/tomli/_parser.py