code: func (qs *queryServer) GetProposal(ctx context.Context, param *GetProposalParam) (proposal *payload.Ballot, err error) {
  	proposal, err = qs.proposalReg.GetProposal(param.Hash)
  	if proposal == nil && err == nil {
  		err = fmt.Errorf("proposal %x not found", param.Hash)
  	}
  	return
  }
docs: // proposals