title: Is SolrJ 7.7.3 Backward compatible with SolrJ 6.6?
body: <p>I am using SolrJ client 7.7 in one of my service and SolrJ client 6.6 in another.
  So just want to know if,
  Is SolrJ 7.7.3 Backward compatible with SolrJ 6.6?</p>