__getRequestHeaders(raw, AcceptHeader) {
      let headers = {
         'Content-Type': 'application/json;charset=UTF-8',
         'Accept': 'application/vnd.github.' + (AcceptHeader || this.__AcceptHeader),
      };

      if (raw) {
         headers.Accept += '.raw';
      }
      headers.Accept += '+json';

      if (this.__authorizationHeader) {
         headers.Authorization = this.__authorizationHeader;
      }

      return headers;
   }
Compute the headers required for an API request.
@private
@param {boolean} raw - if the request should be treated as JSON or as a raw request
@param {string} AcceptHeader - the accept header for the request
@return {Object} - the headers to use in the request