Function map_protocol_err 

pub fn map_protocol_err(err: &FinamError) -> Error

Errors of queries and subscriptions. Commands use map_command_err.

RESOURCE_EXHAUSTED becomes [Error::RateLimited] with a fixed retry_after of one second. Finam documents the quota (200 requests per minute) but not the wait, so the pause is a guess, not verified against the live API.