he value must be at most this length
    min_length: The value must be at least this length
    strip_whitespace: Whether to strip whitespace from the value
    to_lower: Whether to convert the value to lowercase
    to_upper: Whether to convert the value to uppercase
    regex_engine: The regex engine to use for pattern validation. Default is 'rust-regex'.
        - `rust-regex` uses the [`regex`](https://docs.rs/regex) Rust
          crate, which is non-backtracking and therefore more DDoS
          resistant, but does not support all regex features.
        - `python-re` use the [`re`](https://docs.python.org/3/library/re.html) module,
          which supports all regex features, but may be slower.
    strict: Whether the value should be a string or a value that can be converted to a string
    coerce_numbers_to_str: Whether to enable coercion of any `Number` type to `str` (not applicable in `strict` mode).
    ref: optional unique identifier of the schema, used to reference the schema in other places
    metadata: Any other information you want to include with the schema, not used by pydantic-core
    serialization: Custom serialization schema
r