code: def wr_title(self, worksheet, row_idx=0):
          
          if self.vars.title is not None:
              # Title is one line
              if isinstance(self.vars.title, str):
                  return self.wr_row_mergeall(worksheet, self.vars.title, self.fmt_hdr, row_idx)
              # Title is multi-line
              else:
                  ridx = row_idx
                  for title_line in self.vars.title:
                      ridx = self.wr_row_mergeall(worksheet, title_line, self.fmt_hdr, ridx)
                  return ridx
          return row_idx
docs: Write title (optional).