code: function fnAppendBusyIndicator() {
  
  		// Only append if busy state is still set
  		if (!this.getBusy()) {
  			return;
  		}
  
  		var $this = this.$(this._sBusySection);
  
  		//If there is a pending delayed call to append the busy indicator, we can clear it now
  		if (this._busyIndicatorDelayedCallId) {
  			clearTimeout(this._busyIndicatorDelayedCallId);
  			delete this._busyIndicatorDelayedCallId;
  		}
  
  		// if no busy section/control jquery instance could be retrieved -> the control is not part of the dom anymore
  		// this might happen in certain scenarios when e.g. a dialog is closed faster than the busyIndicatorDelay
  		if (!$this || $this.length === 0) {
  			Log.warning("BusyIndicator could not be rendered. The outer control instance is not valid anymore.");
  			return;
  		}
  
  		if (this._sBlockSection === this._sBusySection) {
  			if (this._oBlockState) {
  				BusyIndicatorUtils.addHTML(this._oBlockState, this.getBusyIndicatorSize());
  
  				BlockLayerUtils.toggleAnimationStyle(this._oBlockState, true);
  
  				this._oBusyBlockState = this._oBlockState;
  
  			} else {
  				// BusyIndicator is the first blocking element created (and )
  				fnAddStandaloneBusyIndicator.call(this);
  			}
  		} else {
  			// Standalone busy indicator
  			fnAddStandaloneBusyIndicator.call(this);
  		}
  	}
docs: Add busy indicator to DOM
  
  @private