public synchronized boolean contains(long index) {
		if (lastRange != null && lastRange.contains(index)) {
			return true;
		}
		
		int pos = getPositionOfRangeAtOrBefore(new ObjectValueRange<T>(index, index, null));		
		if (pos < 0) {
			return false;
		}
		lastRange = ranges.get(pos);
		
		return lastRange.contains(index);
	}
Returns true if the associated index has an associated object even if the assocated object
is null. 
@param index the index to check for an association.
@return true if the associated index has an associated object even if the assocated object
is null.
Ghidra/Framework/Generic/src/main/java/ghidra/util/datastruct/ObjectRangeMap.java