elk-reasoner/src/main/java/org/semanticweb/elk/reasoner/taxonomy/hashing/NodeHasher.java
@Override
	public int hash(Node<? extends ElkEntity> node) {
		if (node.size() >= cacheNodeMemberNo) {
			if (hashCache.containsKey(node)) {
				return hashCache.get(node);
			}
			// else
			int hash = HashGenerator.combineMultisetHash(true, node,
					elkEntityHasher);
			hashCache.put(node, hash);
			return hash;
		}
		// else
		return HashGenerator.combineMultisetHash(true, node, elkEntityHasher);
	}
@Override
	public int hash(Node<? extends ElkEntity> node) {
		if (node.size() >= cacheNodeMemberNo) {
			if (hashCache.containsKey(node)) {
				return hashCache.get(node);
			}
			// else
			int hash = HashGenerator.combineMultisetHash(true, node,
					elkEntityHasher);
			hashCache.put(node, hash);
			return hash;
		}
		// else
		return HashGenerator.combineMultisetHash(true, node, elkEntityHasher);
	}
Compute the hash for an entity node. This method implements a simple
cache for nodes with unusually large numbers of members. This mainly
covers the case where a huge number of classes is equal to owl:Nothing
due to modelling errors.

@param node
@return the has for the given entity node