elk-reasoner/src/main/java/org/semanticweb/elk/reasoner/indexing/classes/CachedIndexedObjectPropertyImpl.java
private int indexOf(IndexedPropertyChain subChain, ElkAxiom reason) {
		for (int i = 0; i < toldSubChains_.size(); i++) {
			if (toldSubChains_.get(i).equals(subChain)
					&& toldSubChainsReasons_.get(i).equals(reason))
				return i;
		}
		// else not found
		return -1;
	}
private int indexOf(IndexedPropertyChain subChain, ElkAxiom reason) {
		for (int i = 0; i < toldSubChains_.size(); i++) {
			if (toldSubChains_.get(i).equals(subChain)
					&& toldSubChainsReasons_.get(i).equals(reason))
				return i;
		}
		// else not found
		return -1;
	}
TODO: create a generic method for this operation (used in other places)