t v.validate_python({'a': b'hello '}) == {'a': 'hello world'}
```

Args:
    function: The validator function to call
    field_name: The name of the field this validator is applied to, if any (deprecated)
    schema: The schema to validate the output of the validator function
    ref: optional unique identifier of the schema, used to reference the schema in other places
    json_schema_input_schema: The core schema to be used to generate the corresponding JSON Schema input type
    metadata: Any other information you want to include with the schema, not used by pydantic-core
    serialization: Custom serialization schema
z–The `field_name` argument on `with_info_before_validator_function` is deprecated, it will be passed to the function through `ValidationState` instead.©