boolean execute() {
		message = "";
		Instruction inst = program.getListing().getInstructionContaining(currentAddr);
		Address ftAddr = inst.getFallThrough();
		if (ftAddr == null ||
			!inst.getFallThrough().equals(currentFallthroughAddr)) {
			executingCommand = true;
			SetFallThroughCmd cmd = new SetFallThroughCmd(inst.getMinAddress(), 
														currentFallthroughAddr);
			tool.execute(cmd, program);
			message = "Updated Fallthrough address";
			executingCommand = false;
			if (defaultFallthroughAddr != null && 
				defaultFallthroughAddr.equals(currentFallthroughAddr)) {
				isDefault = true;
				isUserDefined = false;					
			}
		}
		else {
			message = "No changes were made";
		}
		listener.stateChanged(null);
		return true;
	}
Execute the command to set the fall-through.
@return true if the input was valid
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/fallthrough/FallThroughModel.java