internalize ackhandler and congestion

internal/congestion/bandwidth_test.go

@@ -0,0 +1,14 @@
+package congestion
+
+import (
+	"time"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Bandwidth", func() {
+	It("converts from time delta", func() {
+		Expect(BandwidthFromDelta(1, time.Millisecond)).To(Equal(1000 * BytesPerSecond))
+	})
+})