code: public void applyToClient (Name username, final ClientOp clop)
      {
          resolveClientObject(username, new ClientResolutionListener() {
              public void clientResolved (Name username, ClientObject clobj) {
                  try {
                      clop.apply(clobj);
  
                  } catch (Exception e) {
                      log.warning("Client op failed", "username", username, "clop", clop, e);
  
                  } finally {
                      releaseClientObject(username);
                  }
              }
  
              public void resolutionFailed (Name username, Exception reason) {
                  clop.resolutionFailed(reason);
              }
          });
      }
docs: Resolves the specified client, applies the supplied client operation to them and releases
  the client.