Add aggregate root core class

Author: stevejkang

src/shared/core/AggregateRoot.ts

@@ -0,0 +1,17 @@
+interface AggregateObjectProps {
+  [index: string]: any;
+}
+
+export abstract class AggregateRoot<T extends AggregateObjectProps> {
+  public props: T;
+  protected readonly _id: number;
+
+  protected constructor(props: T, id: number) {
+    this.props = { ...props };
+    this._id = id;
+  }
+
+  get id(): number {
+    return this._id;
+  }
+}