public void markupAddressIfUndefined(Address addr, DataType dt) throws IOException {
		Data data = DataUtilities.getDataAtAddress(program, addr);
		if (data == null || Undefined.isUndefined(data.getBaseDataType())) {
			markupAddress(addr, dt);
		}
	}
Applies the specified {@link DataType} to the specified {@link Address}.

@param addr location to place DataType
@param dt {@link DataType}
@throws IOException if error marking up address
Ghidra/Features/Base/src/main/java/ghidra/app/util/bin/format/golang/structmapping/MarkupSession.java