}
public CellStyle buildHeaderCellStyle(Sheet sheet){
CellStyle cellStyle = sheet.getWorkbook().createCellStyle();
cellStyle.setAlignment(CellStyle.ALIGN_LEFT);
cellStyle.setVerticalAlignment(CellStyle.ALIGN_CENTER);
cellStyle.setFillForegroundColor(IndexedColors.AQUA.getIndex());
cellStyle.setFillPattern(CellStyle.SOLID_FOREGROUND);
cellStyle.setBorderBottom(CellStyle.BORDER_THIN);
cellStyle.setBorderLeft(CellStyle.BORDER_THIN);
cellStyle.setBorderRight(CellStyle.BORDER_THIN);
cellStyle.setBorderTop(CellStyle.BORDER_THIN);
cellStyle.setLeftBorderColor(IndexedColors.DARK_BLUE.getIndex());
cellStyle.setRightBorderColor(IndexedColors.DARK_BLUE.getIndex());
cellStyle.setBottomBorderColor(IndexedColors.DARK_BLUE.getIndex());
cellStyle.setTopBorderColor(IndexedColors.DARK_BLUE.getIndex());
Font font = sheet.getWorkbook().createFont();
font.setFontHeightInPoints((short)14);
font.setFontName("Arial");
font.setColor(IndexedColors.DARK_BLUE.getIndex());
font.setBoldweight(Font.BOLDWEIGHT_BOLD);
cellStyle.setFont(font);
return cellStyle;
}