The [`String::from_utf8_lossy` ](https://doc.rust-lang.org/std/string/struct.String.html#method.from_utf8_lossy) is a std library API, and will replace all invalid utf8 char with `\ufffd`.
The
String::from_utf8_lossyis a std library API, and will replace all invalid utf8 char with\ufffd.