Function fetch 

pub fn fetch<T: Transport>(
    client: &Client<T>,
    request: &ElevationRequest,
    now_s: u64,
) -> Result<(Vec<Elevation>, Fetched), ElevationError>

Fetches request through client and reads each place’s height above mean sea level.

The answer comes from the client’s cache while fresh (see ElevationRequest::source); offline, from the cache only. The Fetched says which, carries ATTRIBUTION and holds the body. Only an answer that parse reads is cached (Client::fetch_checked): one that doesn’t never takes a good copy’s place, and online a stale good copy is returned instead, with the reason.

Errors

ElevationError::Request for a bad request; ElevationError::Net when the fetch fails, or with NetError::Refused naming what parse refused when the only answer there is doesn’t parse.