oauth1.0_token(endpoint, app, permission = NULL, as_header = TRUE,
  private_key = NULL, cache = getOption("httr_oauth_cache"))oauth_endpointoauth_appTRUE, the default, sends oauth in header.
If FALSE, adds as parameter to url.read_key.
Used for signed OAuth 1.0.TRUE means to cache
using the default cache file .oauth-httr, FALSE means
don't cache, and NA means to guess using some sensible heuristics.
A string mean use the specified pToken1.0 reference class (RC) object.Token for full details about the token object, and the
caching policies used to store credentials across sessions.oauth2.0_token,
  oauth_app, oauth_endpoint,
  oauth_service_token