code: func (t *transformer) generateClients(file *ast.File, s *service) error {
  	switch newDecls, err := t.generateClient(s.protoPackageName, s.name, s.clientIface); {
  	case err != nil:
  		return err
  	case len(newDecls) > 0:
  		insertAST(file, s.clientIfaceDecl, newDecls)
  		return nil
  	default:
  		return nil
  	}
  }
docs: // generateClients finds client interface declarations
  // and inserts pRPC implementations after them.