private boolean executeCommand() {

		FlowOverride flow = FlowOverride.NONE;
		Object choice = flowOverrideComboBox.getSelectedItem();
		if (!DEFAULT_CHOICE.equals(choice)) {
			flow = (FlowOverride) choice;
		}

		if (instruction == null) {
			tool.executeBackgroundCommand(new SetFlowOverrideCmd(selection, flow), program);
		}
		else if (instruction.getFlowOverride() == flow) {
			return true;
		}
		else {
			tool.executeBackgroundCommand(new SetFlowOverrideCmd(instruction.getMinAddress(), flow),
				program);
		}
		return true;
	}
Called when the user initiates changes that need to be put into a 
command and executed. 

@return true if the command was successfully created.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/disassembler/SetFlowOverrideDialog.java