Method dequeue

src/cpp-ethereum/libethereum/BlockQueue.h:96–104

	}

	T dequeue()
	{
		T t;
		std::swap(t, m_queue.front());
		m_queue.pop_front();
		m_size -= t.blockData.size();

		return t;
	}

	std::vector<T> dequeueMultiple(std::size_t _n)
	{