fix and add tests

spf2_test.go

@@ -6,10 +6,10 @@ import (
 
 func TestSpf2(t *testing.T) {
 	c := NewClient()
-	defer c.Free()
+	defer c.Close()
 
-	req := newRequest(c)
-	defer req.Free()
+	req := newRequest(c.(*clientImpl))
+	defer req.free()
 
 	err := req.setIPv4Addr("173.194.39.150")
 	if err != nil {
@@ -33,3 +33,15 @@ func TestSpf2(t *testing.T) {
 		t.Fatal(s)
 	}
 }
+
+func TestInterface(t *testing.T) {
+	client := NewClient()
+	defer client.Close()
+	res, err := client.Query("gmail.com", "173.194.39.150")
+	if err != nil {
+		t.Fatalf("client.Query() err = %v, expected nil", err)
+	}
+	if s := res.String(); s != "pass" {
+		t.Fatal(s)
+	}
+}