code: def to_escpos(self):
          
          cmd = ''
          ordered_cmds = self.cmds.keys()
          ordered_cmds.sort(lambda x,y: cmp(self.cmds[x]['_order'], self.cmds[y]['_order']))
          for style in ordered_cmds:
              cmd += self.cmds[style][self.get(style)]
          return cmd
docs: converts the current style to an escpos command string