utils: add clear() for AdvancedBuffer

src/utils/advanced-buffer.js

@@ -67,6 +67,13 @@ export class AdvancedBuffer extends EventEmitter {
     return this._buffer;
   }
 
+  /**
+   * clear staged buffer
+   */
+  clear() {
+    this._buffer = Buffer.alloc(0);
+  }
+
   /**
    * digest a buffer, emit an event if a complete packet was resolved
    * @param buffer{Buffer}: a buffer to be digested