private void moveBlock() {
		if (!program.canLock()) {
			setStatusText("Program is busy, try again later");
			return;
		}
		MemoryBlock block = getSelectedBlock();
		if (block == null) {
			return;
		}

		if (block.isOverlay() && block.getStart().isNonLoadedMemoryAddress()) {
			// impose convention-based restriction
			Msg.showInfo(getClass(), getComponent(), "Moving OTHER Overlay Block Not Allowed",
				"OTHER overlay blocks cannot be moved.");
		}
		else {
			showMoveBlockDialog(block);
		}
	}
Pop up a dialog to expand the block either up or down; "up" means make a
block have a lesser starting address; "down" means to make the block have
a greater ending address.

@param dialogType either ExpandBlockDialog.EXPAND_UP or
           ExpandBlockDialog.EXPAND_DOWN.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/memory/MemoryMapProvider.java