public Font createFont(WriteFont writeFont, Font originFont, boolean useCache) {
        if (!useCache) {
            return StyleUtil.buildFont(workbook, originFont, writeFont);
        }
        WriteFont tempWriteFont = new WriteFont();
        WriteFont.merge(writeFont, tempWriteFont);

        Font font = fontMap.get(tempWriteFont);
        if (font != null) {
            return font;
        }
        font = StyleUtil.buildFont(workbook, originFont, tempWriteFont);
        fontMap.put(tempWriteFont, font);
        return font;
    }
create a font.

@param writeFont
@param originFont
@param useCache
@return
fastexcel-core/src/main/java/cn/idev/excel/write/metadata/holder/WriteWorkbookHolder.java