lo' in v
    return v + ' world'

fn_schema = core_schema.with_info_plain_validator_function(function=fn)
schema = core_schema.chain_schema(
    [fn_schema, fn_schema, fn_schema, core_schema.str_schema()]
)
v = SchemaValidator(schema)
assert v.validate_python('hello') == 'hello world world world'
```

Args:
    steps: The schemas to chain
    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
Ú