in R/auth.R [31:39]
token_from_response <- function(response) {
cont <- httr::content(response, as = "parsed")
if (is.null(cont[["access_token"]])) {
stop("Response does not contain a token.")
}
date <- response[["date"]]
expiry <- as.POSIXct(date) + cont[["expires_in"]]
graph_api_token(cont[["access_token"]], expiry, retrieved = date)
}