Interface update, per-method Contexts.

docs/present/lightning/gae_test.go

 // +build !native_appengine
 
 package demo
 
 import "testing"
 import "golang.org/x/net/context"
 import "github.com/luci/gae/impl/memory"
 import . "github.com/smartystreets/goconvey/convey"
 
 // START OMIT
 
 import "github.com/luci/gae/service/datastore" // HL
 
 func TestGAE(t *testing.T) {
         type Model struct { // HL
                 ID   string `gae:"$id"` // HL
                 A, B int    // HL
         } // HL
         Convey("Put/Get w/ gae", t, func() {
                 ctx := memory.Use(context.Background())
-                ds := datastore.Get(ctx) // get datastore client
-                So(ds.Put(               // HL
+                So(datastore.Put(ctx, // HL
                         &Model{"one thing", 10, 20},                // HL
                         &Model{"or another", 20, 30}), ShouldBeNil) // HL
                 ms := []*Model{{ID: "one thing"}, {ID: "or another"}}
-                So(ds.Get(ms), ShouldBeNil) // HL
+                So(datastore.Get(ctx, ms), ShouldBeNil) // HL
                 So(ms, ShouldResemble, []*Model{{"one thing", 10, 20}, {"or another", 20, 30}})
         })
 }
 
 // END OMIT