Fixed bug introduced while cutting/pasting YARD documentation.

Author: jdantonio

lib/concurrent/java_cached_thread_pool.rb

@@ -59,7 +59,7 @@ def wait_for_termination(timeout)
       #
       # @raise [ArgumentError] if no task is given
       def post(*args)
-        raise ArgumentError.new('no block given') unless task_given?
+        raise ArgumentError.new('no block given') unless block_given?
         @executor.submit{ yield(*args) }
         return true
       rescue Java::JavaUtilConcurrent::RejectedExecutionException => ex

lib/concurrent/ruby_cached_thread_pool.rb

@@ -83,7 +83,7 @@ def wait_for_termination(timeout)
     #
     # @raise [ArgumentError] if no block is given
     def post(*args, &task)
-      raise ArgumentError.new('no block given') if task.nil?
+      raise ArgumentError.new('no block given') unless block_given?
       @mutex.synchronize do
         break false unless @state == :running