key, ready = queue.Next()
require.True(t, ready)
require.Equal(t, NodeKey{1, 0}, key)
queue.Done(key)
queue.AddMerge(NodeKey{1, 0})
key, ready = queue.Next()
require.True(t, ready)
require.Equal(t, NodeKey{1, 0}, key)
queue.Done(key)
queue.AddMerge(NodeKey{1, 0})