@Override
    protected void setColumnWidth(WriteSheetHolder writeSheetHolder, List<WriteCellData<?>> cellDataList, Cell cell, Head head,
                                  Integer relativeRowIndex, Boolean isHead) {
        boolean needSetWidth = relativeRowIndex != null && (isHead || relativeRowIndex == 0);
        if (!needSetWidth) {
            return;
        }
        Integer width = columnWidth(head, cell.getColumnIndex());
        if (width != null) {
            width = width * 256;
            writeSheetHolder.getSheet().setColumnWidth(cell.getColumnIndex(), width);
        }
    }
Returns the column width according to each column header

@author Jiaju Zhuang
fastexcel-core/src/main/java/cn/idev/excel/write/style/column/AbstractHeadColumnWidthStyleStrategy.java