mongo.rb in mongo-1.12.1

- old
+ new

@@ -77,9 +77,10 @@
 
 require 'bson'
 
 require 'set'
 require 'thread'
+require 'monitor'
 
 require 'mongo/utils'
 require 'mongo/exception'
 require 'mongo/functional'
 require 'mongo/connection'