add missing file (#39)

Author: maxkaneco

v2/portfolio/dust_service.go

@@ -0,0 +1,44 @@
+package portfolio
+
+import (
+	"context"
+
+	"github.com/photon-storage/go-binance/v2"
+)
+
+type DustTransferService struct {
+	Ms *binance.DustTransferService
+}
+
+func (s *DustTransferService) Asset(asset []string) *DustTransferService {
+	s.Ms.Asset(asset)
+	return s
+}
+
+func (s *DustTransferService) MarginAccount() *DustTransferService {
+	s.Ms.MarginAccount()
+	return s
+}
+
+func (s *DustTransferService) Do(
+	ctx context.Context,
+	opts ...binance.RequestOption,
+) (*binance.DustTransferResponse, error) {
+	return s.Ms.Do(ctx)
+}
+
+type DustListService struct {
+	Ms *binance.ListDustService
+}
+
+func (s *DustListService) MarginAccount() *DustListService {
+	s.Ms.MarginAccount()
+	return s
+}
+
+func (s *DustListService) Do(
+	ctx context.Context,
+	opts ...binance.RequestOption,
+) (*binance.ListDustResponse, error) {
+	return s.Ms.Do(ctx)
+}