@Override
        public boolean equals(final Object obj) {
            if (this == obj)
                return true;
            else if (obj == null || getClass() != obj.getClass())
                return false;
            else {
                SharePartitionKey that = (SharePartitionKey) obj;
                return groupId.equals(that.groupId) && Objects.equals(topicIdPartition, that.topicIdPartition);
            }
        }
The SharePartitionKey is used to uniquely identify a share partition. The key is made up of the
share group id, the topic id and the partition id. The key is used to store the SharePartition
objects in the partition cache map.
core/src/main/java/kafka/server/share/SharePartitionManager.java