First commit.

Signed-off-by: Chen Xiao <abigwc@gmail.com>

client/node_modules/d3-array/src/intersection.js

@@ -0,0 +1,19 @@
+import {InternSet} from "internmap";
+
+export default function intersection(values, ...others) {
+  values = new InternSet(values);
+  others = others.map(set);
+  out: for (const value of values) {
+    for (const other of others) {
+      if (!other.has(value)) {
+        values.delete(value);
+        continue out;
+      }
+    }
+  }
+  return values;
+}
+
+function set(values) {
+  return values instanceof InternSet ? values : new InternSet(values);
+}