code: function checkRejectCall(callExpression) {
              if (!callExpression.arguments.length && ALLOW_EMPTY_REJECT) {
                  return;
              }
              if (
                  !callExpression.arguments.length ||
                  !astUtils.couldBeError(callExpression.arguments[0]) ||
                  callExpression.arguments[0].type === "Identifier" && callExpression.arguments[0].name === "undefined"
              ) {
                  context.report({
                      node: callExpression,
                      message: "Expected the Promise rejection reason to be an Error."
                  });
              }
          }
docs: ---------------------------------------------------------------------- Helpers ---------------------------------------------------------------------- 
  Checks the argument of a reject() or Promise.reject() CallExpression, and reports it if it can't be an Error
  @param {ASTNode} callExpression A CallExpression node which is used to reject a Promise
  @returns {void}