hashCode = hash;
        }

        @Override
        public boolean equals(Object obj) {
            if (obj == this) {
                return true;
            } else if (obj == null || !getClass().equals(obj.getClass())) {
                return false;
            }

            Key that = (Key) obj;
            return artifactId.equals(that.artifactId)
                    && groupId.equals(that.groupId)