veyron/services/wsprd/principal: Changes correpsonding to
https://veyron-review.googlesource.com/6273

Change-Id: Ib781546ac6fa28889e1eac9491bb8e87478ad6e4
diff --git a/services/wsprd/principal/util_test.go b/services/wsprd/principal/util_test.go
index a914796..1afd10a 100644
--- a/services/wsprd/principal/util_test.go
+++ b/services/wsprd/principal/util_test.go
@@ -3,6 +3,7 @@
 import (
 	"fmt"
 	"strings"
+	"time"
 
 	vsecurity "veyron.io/veyron/veyron/security"
 
@@ -15,7 +16,9 @@
 	local  security.Principal
 }
 
+func (c *context) Timestamp() (t time.Time)                  { return t }
 func (c *context) Method() string                            { return c.method }
+func (c *context) MethodTags() []interface{}                 { return nil }
 func (c *context) Name() string                              { return "" }
 func (c *context) Suffix() string                            { return "" }
 func (c *context) Label() security.Label                     { return 0 }