code: def get_opcode(self, script, pc, verify_minimal_data=False):
          
          opcode = indexbytes(script, pc)
          decoder = self.decoder.get(opcode)
          # lambda s, p, verify_minimal_data: (p+1, None))
          if decoder:
              pc, data = decoder(script, pc, verify_minimal_data=verify_minimal_data)
              is_ok = (data is not None)
          else:
              pc += 1
              data = None
              is_ok = True
          return opcode, data, pc, is_ok
docs: Step through the script, returning a tuple with the next opcode, the next
          piece of data (if the opcode represents data), the new PC, and a boolean indicated
          valid parsing.