docs: public static VelocityEngine newEngine(String templateDir, String charset) {
  		final VelocityEngine ve = new VelocityEngine();
  
  		ve.setProperty(Velocity.FILE_RESOURCE_LOADER_CACHE, true); // 使用缓存
  		ve.init(_newInitedProp(templateDir, charset));
  
  		return ve;
  	}