warning: associated items `deser_from_str` and `ser_to_string` are never used
   --> src/store/compressors.rs:93:8
    |
92  | impl ZstdCompressor {
    | ------------------- associated items in this implementation
93  |     fn deser_from_str(val: &str) -> Result<ZstdCompressor, String> {
    |        ^^^^^^^^^^^^^^
...
129 |     fn ser_to_string(&self) -> String {
    |        ^^^^^^^^^^^^^
    |
    = note: `#[warn(dead_code)]` on by default