public static WriteCellStyle build(StyleProperty styleProperty, FontProperty fontProperty) {
        if (styleProperty == null && fontProperty == null) {
            return null;
        }
        WriteCellStyle writeCellStyle = new WriteCellStyle();
        buildStyleProperty(styleProperty, writeCellStyle);
        buildFontProperty(fontProperty, writeCellStyle);
        return writeCellStyle;
    }
The source is not empty merge the data to the target.

@param styleProperty styleProperty
@param fontProperty  fontProperty
fastexcel-core/src/main/java/cn/idev/excel/write/metadata/style/WriteCellStyle.java