How to use the metal-dom.dom.removeChildren function in metal-dom

replaceSurfaceContent_(surfaceElementId, surface, content) {
		content = this.replaceSurfacePlaceholders_(content, surfaceElementId, surface);
		if (surfaceElementId === this.component_.id) {
			this.replaceElementContent(content);
			return;
		}

		var el = this.getSurfaceElement(surfaceElementId);
		var frag = this.buildFragment_(content);
		var element = this.findElementInContent_(surfaceElementId, frag);
		if (element) {
			surface.element = element;
			dom.replace(el, surface.element);
		} else {
			dom.removeChildren(el);
			dom.append(el, frag);
		}
	}

if (!element) {
			if (newElement) {
				this.component_.element = newElement;
				return;
			} else {
				this.component_.element = document.createElement('div');
				element = this.component_.element;
			}
		}

		if (newElement) {
			this.updateElementAttributes_(element, newElement);
			newContent = newElement.childNodes;
		}

		dom.removeChildren(element);
		dom.append(element, newContent);
	}