lib/createsend/createsend.rb
def refresh_token
      if not @auth_details or
        not @auth_details.has_key? :refresh_token or
        not @auth_details[:refresh_token]
        raise '@auth_details[:refresh_token] does not contain a refresh token.'
      end

      access_token, expires_in, refresh_token =
        self.class.refresh_access_token @auth_details[:refresh_token]
      auth({
        :access_token => access_token,
        :refresh_token => refresh_token})
      [access_token, expires_in, refresh_token]
    end
def refresh_token
      if not @auth_details or
        not @auth_details.has_key? :refresh_token or
        not @auth_details[:refresh_token]
        raise '@auth_details[:refresh_token] does not contain a refresh token.'
      end

      access_token, expires_in, refresh_token =
        self.class.refresh_access_token @auth_details[:refresh_token]
      auth({
        :access_token => access_token,
        :refresh_token => refresh_token})
      [access_token, expires_in, refresh_token]
    end
Refresh the current OAuth token using the current refresh token.