code: public List<String> getHeader() {
  		if (false == config.containsHeader) {
  			throw new IllegalStateException("No header available - header parsing is disabled");
  		}
  		if (lineNo == 0) {
  			throw new IllegalStateException("No header available - call nextRow() first");
  		}
  		return header.fields;
  	}
docs: 获取头部字段列表，如果containsHeader设置为false则抛出异常
  
  @return 头部列表
  @throws IllegalStateException 如果不解析头部或者没有调用nextRow()方法