Adds documentations for adapters and main constructors (#4951)

* wip

* Adds documentations for adapters, and constructors

* nits

* nit

src/Adapters/PubSub/PubSubAdapter.js

@@ -0,0 +1,49 @@
+/*eslint no-unused-vars: "off"*/
+/**
+ * @module Adapters
+ */
+/**
+ * @interface PubSubAdapter
+ */
+export class PubSubAdapter {
+  /**
+   * @returns {PubSubAdapter.Publisher}
+   */
+  static createPublisher() {}
+  /**
+   * @returns {PubSubAdapter.Subscriber}
+   */
+  static createSubscriber() {}
+}
+
+/**
+ * @interface Publisher
+ * @memberof PubSubAdapter
+ */
+interface Publisher {
+  /**
+   * @param {String} channel the channel in which to publish
+   * @param {String} message the message to publish
+   */
+  publish(channel: string, message: string):void;
+}
+
+/**
+ * @interface Subscriber
+ * @memberof PubSubAdapter
+ */
+interface Subscriber {
+  /**
+   * called when a new subscription the channel is required
+   * @param {String} channel the channel to subscribe
+   */
+  subscribe(channel: string): void;
+
+  /**
+   * called when the subscription from the channel should be stopped
+   * @param {String} channel
+   */
+  unsubscribe(channel: string): void;
+}
+
+export default PubSubAdapter;