docs: def header(self, sheet, name):
          """
          Write sheet header.
          Args:
              sheet: (xlwt.Worksheet.Worksheet) instance of xlwt sheet.
              name: (unicode) name of sheet.
          """
  
          header = sheet.row(0)
          for i, column in enumerate(self.headers[name]):
              header.write(i, self.headers[name][i])