code: func (s *SupportImpl) GetLedgerHeight(channelID string) (uint64, error) {
  	lgr := s.Peer.GetLedger(channelID)
  	if lgr == nil {
  		return 0, errors.Errorf("failed to look up the ledger for Channel %s", channelID)
  	}
  
  	info, err := lgr.GetBlockchainInfo()
  	if err != nil {
  		return 0, errors.Wrap(err, fmt.Sprintf("failed to obtain information for Channel %s", channelID))
  	}
  
  	return info.Height, nil
  }
docs: // GetLedgerHeight returns ledger height for given channelID