Remove the `NoPrune` method

preload.go

@@ -13,7 +13,6 @@ type Preload struct {
 	path []string
 	cols []string
 	cond builder.Cond
-	noPrune bool
 }
 
 // NewPreload creates a new preload with the specified path
@@ -36,12 +35,6 @@ func (p *Preload) Where(cond builder.Cond) *Preload {
 	return p
 }
 
-// NoPrune sets a flag to avoid pruning empty associations
-func (p *Preload) NoPrune() *Preload {
-	p.noPrune = true
-	return p
-}
-
 // PreloadTreeNode is a tree node for the association preloads
 type PreloadTreeNode struct {
 	preload     *Preload
@@ -150,7 +143,7 @@ func (node *PreloadTreeNode) compute(session *Session, ownMap, pruneMap reflect.
 	}
 
 	var refPruneMap reflect.Value
-	if len(node.children) > 0 && !(node.preload != nil && (len(node.preload.cols) > 0 || node.preload.noPrune)) {
+	if len(node.children) > 0 && !(node.preload != nil && len(node.preload.cols) > 0) {
 		refPruneMap = reflect.MakeMap(reflect.MapOf(refMap.Type().Key(), reflect.TypeOf(true)))
 		refIter := refMap.MapRange()
 		for refIter.Next() {

preload_test.go

@@ -62,7 +62,7 @@ insert into employee_indication values (1,2), (1,3), (2,3), (2,4), (2,5), (3,5),
 	var employee Employee
 	_, err = engine.Preloads(
 		engine.Preload("Indications.Buddy").Cols("name"),
-		engine.Preload("Indications").NoPrune(),
+		engine.Preload("Indications").Cols("id"),
 	).Cols("name").Where(builder.Eq{"id": 2}).Get(&employee)
 	require.NoError(t, err)