code: public static final String GET_STG_NAME(STGroup stg){
  		String ret = null;
  		if(stg instanceof STGroupFile){
  			ret = ((STGroupFile)stg).fileName;
  		}
  		else if(stg instanceof STGroupString){
  			ret = ((STGroupString)stg).sourceName;
  		}
  		else if(stg instanceof STGroupDir){
  			ret = ((STGroupDir)stg).groupDirName;
  		}
  		return StringUtils.substringBeforeLast(ret, ".");
  	}
docs: Returns the name of the STGroup.
  Any file extension will be removed from the returned name.
  @param stg STGroup
  @return name of the group or null