private FunctionSymbol getFunctionSymbol(Address address) {
		SymbolTable symbolTable = program.getSymbolTable();
		Symbol primary = symbolTable.getPrimarySymbol(address);
		if (primary instanceof FunctionSymbol) {
			return (FunctionSymbol) primary;
		}
		return null;
	}
Assumptions:
<ul>
 <li>New label in functions should default to local namespace.
 <li>Editing a default label in a function should default to the local namespace.
 <li>Function symbols user their parent namespace.
</ul>
Ghidra/Features/Base/src/main/java/ghidra/app/util/AddEditDialog.java