@Override
	public default void add(Address addr, Object value) {
		if (value == null) {
			remove(addr);
			return;
		}
		if (!(value instanceof String)) {
			throw new IllegalArgumentException("String value required");
		}
		add(addr, (String) value);
	}
Get the String value at the given address.
@param addr the address from where to get the String value
@return String or null if property not found at addr.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/util/StringPropertyMap.java