Let us just add a try/catch block:
public boolean drop() { try { getMongoCollection().drop(); return true; } catch (Exception e) { return false; } }
With this implementation, we are finished with the TicTacToeCollection class that acts as a layer between our main class and MongoDB.
The source code can be found in the 02-save-move branch of the tdd-java-ch06-tic-tac-toe-mongo Git repository (https://bitbucket.org/vfarcic/tdd-java-ch06-tic-tac-toe-mongo/branch/02-save-move). The classes in particular are TicTacToeCollectionSpec and TicTacToeCollection.