public static boolean isValidPointer(Data pointerData) {
		Program program = pointerData.getProgram();
		Memory memory = program.getMemory();
		Address refAddr = (Address) pointerData.getValue();
		if (memory.contains(refAddr)) {
			return true;
		}
		Symbol primary = program.getSymbolTable().getPrimarySymbol(refAddr);
		return primary != null && primary.getSource() != SourceType.DEFAULT;
	}
Determine if pointerData refers to a valid memory address or symbol
@param pointerData pointer data
@return true if pointer data refers to valid memory address or symbol
Ghidra/Features/Base/src/main/java/ghidra/app/util/bin/format/elf/ElfDefaultGotPltMarkup.java