docs: public ExcelWriter merge(int lastColumn, Object content, boolean isSetHeaderStyle) {
  		Assert.isFalse(this.isClosed, "ExcelWriter has been closed!");
  
  		final int rowIndex = this.currentRow.get();
  		merge(rowIndex, rowIndex, 0, lastColumn, content, isSetHeaderStyle);
  
  		// 设置内容后跳到下一行
  		if (null != content) {
  			this.currentRow.incrementAndGet();
  		}
  		return this;
  	}