code: func (api OrganizationsAPI) DeleteUserGrant(w http.ResponseWriter, r *http.Request) {
  	globalid := mux.Vars(r)["globalid"]
  	userIdentifier := mux.Vars(r)["username"]
  	grantString := mux.Vars(r)["grant"]
  
  	grant := grants.Grant(grantString)
  
  	userObj, err := SearchUser(r, userIdentifier)
  	if err != nil && !db.IsNotFound(err) {
  		log.Error("Failed to look up user identifier: ", err)
  		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
  		return
  	}
  	if err != nil {
  		// No user found for this identifier, since the user thus no longer has the grant requested
  		// for removal, we can also return a 204 here
  		w.WriteHeader(http.StatusNoContent)
  		return
  	}
  
  	hasAuth, err := hasAuthorization(r, userObj.Username, globalid)
  	if handleServerError(w, "checking if user has an authorization for the organization", err) {
  		return
  	}
  	if !hasAuth {
  		log.Debug("Refusing to delete grant for user without authorization")
  		w.WriteHeader(http.StatusForbidden)
  		w.Write([]byte("User does not have an authorization for this organzation"))
  		return
  	}
  
  	grantMgr := grants.NewManager(r)
  	err = grantMgr.DeleteUserGrant(userObj.Username, globalid, grant)
  	if err != nil && !db.IsNotFound(err) {
  		log.Error("Failed to delete user grant: ", err)
  		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
  		return
  	}
  
  	w.WriteHeader(http.StatusNoContent)
  }
docs: // DeleteUserGrant removes a single named grant for the user