can we store it? YES WE CAN

node/impl/storminer.go

@@ -1,6 +1,9 @@
 package impl
 
 import (
+	"context"
+	"io/ioutil"
+
 	"github.com/filecoin-project/go-lotus/api"
 	"github.com/filecoin-project/go-lotus/lib/sectorbuilder"
 )
@@ -11,4 +14,24 @@ type StorageMinerAPI struct {
 	SectorBuilder *sectorbuilder.SectorBuilder
 }
 
+func (sm *StorageMinerAPI) StoreGarbageData(ctx context.Context) (uint64, error) {
+	data := make([]byte, 1024)
+	fi, err := ioutil.TempFile("", "lotus-garbage")
+	if err != nil {
+		return 0, err
+	}
+
+	if _, err := fi.Write(data); err != nil {
+		return 0, err
+	}
+	fi.Close()
+
+	sectorId, err := sm.SectorBuilder.AddPiece("foo", 1024, fi.Name())
+	if err != nil {
+		return 0, err
+	}
+
+	return sectorId, err
+}
+
 var _ api.StorageMiner = &StorageMinerAPI{}