Reorder options.go

options.go

@@ -1,26 +1,26 @@
 package asciitree
 
+type sortOptions struct {
+	dirsFirst bool
+}
+
 // SortOption represents an option that can be provided to the Sort method.
 type SortOption interface {
 	apply(*sortOptions)
 }
 
-type sortOptions struct {
-	dirsFirst bool
-}
-
 type dirsFirstOption bool
 
+func (d dirsFirstOption) apply(opts *sortOptions) {
+	opts.dirsFirst = bool(d)
+}
+
 // WithDirsFirst is an option that makes the Sort method order directories
 // before leaves.
 func WithDirsFirst(value bool) SortOption {
 	return dirsFirstOption(value)
 }
 
-func (d dirsFirstOption) apply(opts *sortOptions) {
-	opts.dirsFirst = bool(d)
-}
-
 func newSortOptions(opts ...SortOption) sortOptions {
 	var options sortOptions
 	for _, o := range opts {