code: @OverrideOnDemand
    @OverridingMethodsMustInvokeSuper
    protected boolean performLocking (@Nonnull final WPECTYPE aWPEC,
                                      @Nonnull final DATATYPE aSelectedObject,
                                      @Nonnull final EWebPageFormAction eFormAction)
    {
      // Lock EDIT and DELETE if an object is present
      // Also lock custom actions if an object is selected
      return eFormAction.isModifying () || eFormAction.isCustom ();
    }
docs: Check if locking should be performed on the current request or not.
  Override with care!
  
  @param aWPEC
  The current web page execution context. Never <code>null</code>.
  @param aSelectedObject
  The currently selected object. Never <code>null</code>.
  @param eFormAction
  The current form action. Never <code>null</code>.
  @return <code>true</code> if locking for the current request should be
  performed, <code>false</code> otherwise.