public ExcelWriter fill(Supplier<Object> supplier, FillConfig fillConfig, WriteSheet writeSheet) {
        excelBuilder.fill(supplier.get(), fillConfig, writeSheet);
        return this;
    }
Fill value to a sheet

@param supplier
@param fillConfig
@param writeSheet
@return
fastexcel-core/src/main/java/cn/idev/excel/ExcelWriter.java