Signup tentatively works

server/db/model/OrderedObject.js

@@ -0,0 +1,29 @@
+export default class OrderedObject {
+    entries = []
+    ids = {}
+
+    add(id, data) {
+        if(this.get(id)) {
+            console.error(`Can't add item ${id}: id already exists`)
+            throw new global.ServerError(400, `Member with this email already exists`)
+        }
+        this.entries.push(data)
+        this.ids[id] = this.entries.length - 1
+    }
+
+    delete(key) {
+        if (typeof key === "number") {
+            return this.entries[key]
+        } else {
+            return this.entries[this.ids[key]]
+        }
+    }
+
+    get(key) {
+        if (typeof key === "number") {
+            return this.entries[key]
+        } else {
+            return this.entries[this.ids[key]]
+        }
+    }
+}