public synchronized boolean hasProperty(long index) {
		ValueStoragePage<T> page = getPage(getPageID(index));
		if (page == null) {
			return false;
		}
		return page.hasProperty(getPageOffset(index));
	}
returns whether there is a property value at index.
@param index the long representation of an address.
Ghidra/Framework/Generic/src/main/java/ghidra/util/map/ValueMap.java