Function request_params 

pub fn request_params(
    target: &dyn ReplayTarget,
    request: &CompletionRequest,
    base: impl FnOnce(&mut BaseInput<'_>) -> Result<Map<String, Value>, EncodeError>,
    raw_at: RawAt,
    rewrites: &[Rewrite],
) -> Result<FinalBody, EncodeError>

The body target sends for request. Reports each refused option (after Completion::prepare none is left), then calls base for the wire’s own encoding of the request, merges the mapped options, then the provider options at the top level, then additional_params as raw_at places them, and applies rewrites in order. The only reader of the request’s options, provider options and additional_params on the completion path.

Errors

When an option or a provider field is refused under OnUnsupported::Error, the request carries provider options that did not serialize, additional_params is not an object or holds a malformed tools or cached-content handle, base fails, or a rewrite refuses the body.