--- /dev/null
+// https://github.com/ljharb/proposal-is-error
+var $export = require('./_export')
+ , cof = require('./_cof');
+
+$export($export.S, 'Error', {
+ isError: function isError(it){
+ return cof(it) === 'Error';
+ }
+});
\ No newline at end of file