code: function checkErrors(response, xhrErrors) {
      let { status, ok } = response;
      if (!ok) {
          if (xhrErrors[status]) {
              xhrErrors[status](response);
          }
      }
  }
docs: Check if a special treatment is specify for a specific error code
  
  @param {Object} response The fetch response
  @param {Object} xhrErrors The specific treatment