# File lib/mongo/collection/view/writable.rb, line 175
        def delete_one(opts = {})
          delete_doc = { Operation::Q => filter, Operation::LIMIT => 1 }
          write_concern = collection.write_concern
          with_session(opts) do |session|
            write_with_retry(session, write_concern) do |server, txn_num|
              apply_collation!(delete_doc, server, opts)
              Operation::Delete.new(
                  :deletes => [ delete_doc ],
                  :db_name => collection.database.name,
                  :coll_name => collection.name,
                  :write_concern => write_concern,
                  :session => session,
                  :txn_num => txn_num
              ).execute(server)
            end
          end
        end