add hw2

node_modules/pac-resolver/dist/isResolvable.js

@@ -0,0 +1,23 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+const util_1 = require("./util");
+/**
+ * Tries to resolve the hostname. Returns true if succeeds.
+ *
+ * @param {String} host is the hostname from the URL.
+ * @return {Boolean}
+ */
+async function isResolvable(host) {
+    const family = 4;
+    try {
+        if (await (0, util_1.dnsLookup)(host, { family })) {
+            return true;
+        }
+    }
+    catch (err) {
+        // ignore
+    }
+    return false;
+}
+exports.default = isResolvable;
+//# sourceMappingURL=isResolvable.js.map