Allow methods to be chained for all CollectionAdminRequests so that code like the following can be written:
Create createCollectionRequest = new Create()
Bulk close for 5.3.0 release
Commit 1681811 from email@example.com in branch 'dev/branches/branch_5x'
[ https://svn.apache.org/r1681811 ]
SOLR-7595: Allow method chaining for all CollectionAdminRequests in Solrj
Commit 1681808 from firstname.lastname@example.org in branch 'dev/trunk'
[ https://svn.apache.org/r1681808 ]
This was slightly more complex because of the hierarchy. In order to make this work, I had to make the base class CollectionAdminRequest as abstract. Though this is a back-compat break but this class is marked as experimental.
I also changed many tests to make use of chaining but I didn't change in all places.