its MToolControl.

Drag and drop reordering of perspective items is now prevented if the
Perspective Switcher tool control has the NoMove tag.

Example usage (programmatic):

// To lock the perspective switcher reordering:
toolControl.getTags().add(IPresentationEngine.NO_MOVE);
// To unlock:
	toolControl.getTags().remove(IPresentationEngine.NO_MOVE);

Otherwise: use the e4 model spy to set this tag