Respond to Doug's comments

rpc_util.go

@@ -190,19 +190,18 @@ func (EmptyCallOption) before(*callInfo) error      { return nil }
 func (EmptyCallOption) after(*callInfo, *csAttempt) {}
 
 // StaticMethod returns a CallOption which specifies that a call is being made
-// to a method that is static, which the method is known at compile time and
-// doesn't change at runtime. This can be used as a signal to stats plugins that
-// this method is safe to include as a key to a measurement.
+// to a method that is static, which means the method is known at compile time
+// and doesn't change at runtime. This can be used as a signal to stats plugins
+// that this method is safe to include as a key to a measurement.
 func StaticMethod() CallOption {
 	return StaticMethodCallOption{}
 }
 
 // StaticMethodCallOption is a CallOption that specifies that a call comes
 // from a static method.
-type StaticMethodCallOption struct{}
-
-func (StaticMethodCallOption) before(*callInfo) error      { return nil }
-func (StaticMethodCallOption) after(*callInfo, *csAttempt) {}
+type StaticMethodCallOption struct {
+	EmptyCallOption
+}
 
 // Header returns a CallOptions that retrieves the header metadata
 // for a unary RPC.