response: gh_response object from a previous gh call, rate limit values are determined from values in the response header. Optional argument, if missing a call to "GET /rate_limit" will be made.
.token: Authentication token. Defaults to GITHUB_PAT or GITHUB_TOKEN environment variables, in this order if any is set. See gh_token() if you need more flexibility, e.g. different tokens for different GitHub Enterprise deployments.
.api_url: Github API url (default: https://api.github.com). Used if endpoint just contains a path. Defaults to GITHUB_API_URL
environment variable if set.
.send_headers: Named character vector of header field values (except Authorization, which is handled via .token). This can be used to override or augment the default User-Agent header: "https://github.com/r-lib/gh".
Returns
A list object containing the overall limit, remaining limit, and the limit reset time.