code: function _request (method, url, options, session) {
      // require options to be object
      options = requireValidOptionalObject(options)
      // set http method
      options.method = method
      // merge arguments into options
      options.uri = url
      // make request
      return request(options, session)
  }
docs: /* private functions 
  @function _request
  
  call request with given method
  
  @param {string} method - http method
  @param {string} url - url to request
  @param {object} options - options
  @param {object} session