@Override
	public boolean applyTo(Program program) {
		SymbolTable st = program.getSymbolTable();
		if (isEntry) {
			st.addExternalEntryPoint(addr);
		}
		else {
			st.removeExternalEntryPoint(addr);
		}
		return true;
	}
Construct a new command for setting/unsetting an external entry point
@param addr address to set or unset as an external entry point.
@param isEntry true if the address is to be an entry. Otherwise, false.
Ghidra/Features/Base/src/main/java/ghidra/app/cmd/label/ExternalEntryCmd.java