docs: add comments

pkg/statistics/handle/autoanalyze/internal/heap/heap.go

@@ -16,6 +16,7 @@
 // 1. Use the `errors` package from PingCAP.
 // 2. Use generics to define the `heapData` struct.
 // 3. Add a peak API.
+// 4. Add an IsEmpty API.
 
 package heap
 
@@ -221,6 +222,7 @@ func (h *Heap[K, V]) Peek() (V, error) {
 	return h.data.items[h.data.queue[0]].obj, nil
 }
 
+// IsEmpty returns true if the heap is empty.
 func (h *Heap[K, V]) IsEmpty() bool {
 	h.lock.RLock()
 	defer h.lock.RUnlock()