diff --git a/go/src/v.io/x/sensorlog/internal/sbmodel/sbmodel.vdl.go b/go/src/v.io/x/sensorlog/internal/sbmodel/sbmodel.vdl.go
index de63374..d32b5d8 100644
--- a/go/src/v.io/x/sensorlog/internal/sbmodel/sbmodel.vdl.go
+++ b/go/src/v.io/x/sensorlog/internal/sbmodel/sbmodel.vdl.go
@@ -44,44 +44,42 @@
 	if err != nil {
 		return err
 	}
-	keyTarget2, fieldTarget3, err := fieldsTarget1.StartField("Desc")
-	if err != vdl.ErrFieldNoExist && err != nil {
-		return err
-	}
-	if err != vdl.ErrFieldNoExist {
-
-		var4 := (m.Desc == "")
-		if var4 {
-			if err := fieldTarget3.FromZero(tt.NonOptional().Field(0).Type); err != nil {
+	var4 := (m.Desc == "")
+	if var4 {
+		if err := fieldsTarget1.ZeroField("Desc"); err != nil && err != vdl.ErrFieldNoExist {
+			return err
+		}
+	} else {
+		keyTarget2, fieldTarget3, err := fieldsTarget1.StartField("Desc")
+		if err != vdl.ErrFieldNoExist {
+			if err != nil {
 				return err
 			}
-		} else {
 			if err := fieldTarget3.FromString(string(m.Desc), tt.NonOptional().Field(0).Type); err != nil {
 				return err
 			}
-		}
-		if err := fieldsTarget1.FinishField(keyTarget2, fieldTarget3); err != nil {
-			return err
-		}
-	}
-	keyTarget5, fieldTarget6, err := fieldsTarget1.StartField("SgPublishSb")
-	if err != vdl.ErrFieldNoExist && err != nil {
-		return err
-	}
-	if err != vdl.ErrFieldNoExist {
-
-		var7 := (m.SgPublishSb == "")
-		if var7 {
-			if err := fieldTarget6.FromZero(tt.NonOptional().Field(1).Type); err != nil {
+			if err := fieldsTarget1.FinishField(keyTarget2, fieldTarget3); err != nil {
 				return err
 			}
-		} else {
+		}
+	}
+	var7 := (m.SgPublishSb == "")
+	if var7 {
+		if err := fieldsTarget1.ZeroField("SgPublishSb"); err != nil && err != vdl.ErrFieldNoExist {
+			return err
+		}
+	} else {
+		keyTarget5, fieldTarget6, err := fieldsTarget1.StartField("SgPublishSb")
+		if err != vdl.ErrFieldNoExist {
+			if err != nil {
+				return err
+			}
 			if err := fieldTarget6.FromString(string(m.SgPublishSb), tt.NonOptional().Field(1).Type); err != nil {
 				return err
 			}
-		}
-		if err := fieldsTarget1.FinishField(keyTarget5, fieldTarget6); err != nil {
-			return err
+			if err := fieldsTarget1.FinishField(keyTarget5, fieldTarget6); err != nil {
+				return err
+			}
 		}
 	}
 	if err := t.FinishFields(fieldsTarget1); err != nil {
@@ -126,14 +124,22 @@
 func (t *VDeviceCfgTarget) FinishField(_, _ vdl.Target) error {
 	return nil
 }
+func (t *VDeviceCfgTarget) ZeroField(name string) error {
+	switch name {
+	case "Desc":
+		t.Value.Desc = ""
+		return nil
+	case "SgPublishSb":
+		t.Value.SgPublishSb = ""
+		return nil
+	default:
+		return fmt.Errorf("field %s not in struct v.io/x/sensorlog/internal/sbmodel.VDeviceCfg", name)
+	}
+}
 func (t *VDeviceCfgTarget) FinishFields(_ vdl.FieldsTarget) error {
 
 	return nil
 }
-func (t *VDeviceCfgTarget) FromZero(tt *vdl.Type) error {
-	*t.Value = VDeviceCfg{}
-	return nil
-}
 
 type KDeviceCfg struct {
 	DevId string
@@ -149,24 +155,23 @@
 	if err != nil {
 		return err
 	}
-	keyTarget2, fieldTarget3, err := fieldsTarget1.StartField("DevId")
-	if err != vdl.ErrFieldNoExist && err != nil {
-		return err
-	}
-	if err != vdl.ErrFieldNoExist {
-
-		var4 := (m.DevId == "")
-		if var4 {
-			if err := fieldTarget3.FromZero(tt.NonOptional().Field(0).Type); err != nil {
+	var4 := (m.DevId == "")
+	if var4 {
+		if err := fieldsTarget1.ZeroField("DevId"); err != nil && err != vdl.ErrFieldNoExist {
+			return err
+		}
+	} else {
+		keyTarget2, fieldTarget3, err := fieldsTarget1.StartField("DevId")
+		if err != vdl.ErrFieldNoExist {
+			if err != nil {
 				return err
 			}
-		} else {
 			if err := fieldTarget3.FromString(string(m.DevId), tt.NonOptional().Field(0).Type); err != nil {
 				return err
 			}
-		}
-		if err := fieldsTarget1.FinishField(keyTarget2, fieldTarget3); err != nil {
-			return err
+			if err := fieldsTarget1.FinishField(keyTarget2, fieldTarget3); err != nil {
+				return err
+			}
 		}
 	}
 	if err := t.FinishFields(fieldsTarget1); err != nil {
@@ -206,14 +211,19 @@
 func (t *KDeviceCfgTarget) FinishField(_, _ vdl.Target) error {
 	return nil
 }
+func (t *KDeviceCfgTarget) ZeroField(name string) error {
+	switch name {
+	case "DevId":
+		t.Value.DevId = ""
+		return nil
+	default:
+		return fmt.Errorf("field %s not in struct v.io/x/sensorlog/internal/sbmodel.KDeviceCfg", name)
+	}
+}
 func (t *KDeviceCfgTarget) FinishFields(_ vdl.FieldsTarget) error {
 
 	return nil
 }
-func (t *KDeviceCfgTarget) FromZero(tt *vdl.Type) error {
-	*t.Value = KDeviceCfg{}
-	return nil
-}
 
 // Sampling script and polling frequency.
 type SamplerDef struct {
@@ -235,24 +245,23 @@
 	if err != nil {
 		return err
 	}
-	keyTarget2, fieldTarget3, err := fieldsTarget1.StartField("Script")
-	if err != vdl.ErrFieldNoExist && err != nil {
-		return err
-	}
-	if err != vdl.ErrFieldNoExist {
-
-		var4 := (m.Script == "")
-		if var4 {
-			if err := fieldTarget3.FromZero(tt.NonOptional().Field(0).Type); err != nil {
+	var4 := (m.Script == "")
+	if var4 {
+		if err := fieldsTarget1.ZeroField("Script"); err != nil && err != vdl.ErrFieldNoExist {
+			return err
+		}
+	} else {
+		keyTarget2, fieldTarget3, err := fieldsTarget1.StartField("Script")
+		if err != vdl.ErrFieldNoExist {
+			if err != nil {
 				return err
 			}
-		} else {
 			if err := fieldTarget3.FromString(string(m.Script), tt.NonOptional().Field(0).Type); err != nil {
 				return err
 			}
-		}
-		if err := fieldsTarget1.FinishField(keyTarget2, fieldTarget3); err != nil {
-			return err
+			if err := fieldsTarget1.FinishField(keyTarget2, fieldTarget3); err != nil {
+				return err
+			}
 		}
 	}
 	var wireValue5 time_2.Time
@@ -260,25 +269,24 @@
 		return err
 	}
 
-	keyTarget6, fieldTarget7, err := fieldsTarget1.StartField("Start")
-	if err != vdl.ErrFieldNoExist && err != nil {
-		return err
-	}
-	if err != vdl.ErrFieldNoExist {
-
-		var8 := (wireValue5 == time_2.Time{})
-		if var8 {
-			if err := fieldTarget7.FromZero(tt.NonOptional().Field(1).Type); err != nil {
+	var8 := (wireValue5 == time_2.Time{})
+	if var8 {
+		if err := fieldsTarget1.ZeroField("Start"); err != nil && err != vdl.ErrFieldNoExist {
+			return err
+		}
+	} else {
+		keyTarget6, fieldTarget7, err := fieldsTarget1.StartField("Start")
+		if err != vdl.ErrFieldNoExist {
+			if err != nil {
 				return err
 			}
-		} else {
 
 			if err := wireValue5.FillVDLTarget(fieldTarget7, tt.NonOptional().Field(1).Type); err != nil {
 				return err
 			}
-		}
-		if err := fieldsTarget1.FinishField(keyTarget6, fieldTarget7); err != nil {
-			return err
+			if err := fieldsTarget1.FinishField(keyTarget6, fieldTarget7); err != nil {
+				return err
+			}
 		}
 	}
 	var wireValue9 time_2.Duration
@@ -286,25 +294,24 @@
 		return err
 	}
 
-	keyTarget10, fieldTarget11, err := fieldsTarget1.StartField("Interval")
-	if err != vdl.ErrFieldNoExist && err != nil {
-		return err
-	}
-	if err != vdl.ErrFieldNoExist {
-
-		var12 := (wireValue9 == time_2.Duration{})
-		if var12 {
-			if err := fieldTarget11.FromZero(tt.NonOptional().Field(2).Type); err != nil {
+	var12 := (wireValue9 == time_2.Duration{})
+	if var12 {
+		if err := fieldsTarget1.ZeroField("Interval"); err != nil && err != vdl.ErrFieldNoExist {
+			return err
+		}
+	} else {
+		keyTarget10, fieldTarget11, err := fieldsTarget1.StartField("Interval")
+		if err != vdl.ErrFieldNoExist {
+			if err != nil {
 				return err
 			}
-		} else {
 
 			if err := wireValue9.FillVDLTarget(fieldTarget11, tt.NonOptional().Field(2).Type); err != nil {
 				return err
 			}
-		}
-		if err := fieldsTarget1.FinishField(keyTarget10, fieldTarget11); err != nil {
-			return err
+			if err := fieldsTarget1.FinishField(keyTarget10, fieldTarget11); err != nil {
+				return err
+			}
 		}
 	}
 	if err := t.FinishFields(fieldsTarget1); err != nil {
@@ -354,14 +361,37 @@
 func (t *SamplerDefTarget) FinishField(_, _ vdl.Target) error {
 	return nil
 }
+func (t *SamplerDefTarget) ZeroField(name string) error {
+	switch name {
+	case "Script":
+		t.Value.Script = ""
+		return nil
+	case "Start":
+		t.Value.Start = func() time.Time {
+			var native time.Time
+			if err := vdl.Convert(&native, time_2.Time{}); err != nil {
+				panic(err)
+			}
+			return native
+		}()
+		return nil
+	case "Interval":
+		t.Value.Interval = func() time.Duration {
+			var native time.Duration
+			if err := vdl.Convert(&native, time_2.Duration{}); err != nil {
+				panic(err)
+			}
+			return native
+		}()
+		return nil
+	default:
+		return fmt.Errorf("field %s not in struct v.io/x/sensorlog/internal/sbmodel.SamplerDef", name)
+	}
+}
 func (t *SamplerDefTarget) FinishFields(_ vdl.FieldsTarget) error {
 
 	return nil
 }
-func (t *SamplerDefTarget) FromZero(tt *vdl.Type) error {
-	*t.Value = SamplerDef{}
-	return nil
-}
 
 // streamdef : <DevId>/<StreamId>
 // Configures a stream of data to be measured.
@@ -384,65 +414,62 @@
 	if err != nil {
 		return err
 	}
-	keyTarget2, fieldTarget3, err := fieldsTarget1.StartField("Desc")
-	if err != vdl.ErrFieldNoExist && err != nil {
-		return err
-	}
-	if err != vdl.ErrFieldNoExist {
-
-		var4 := (m.Desc == "")
-		if var4 {
-			if err := fieldTarget3.FromZero(tt.NonOptional().Field(0).Type); err != nil {
+	var4 := (m.Desc == "")
+	if var4 {
+		if err := fieldsTarget1.ZeroField("Desc"); err != nil && err != vdl.ErrFieldNoExist {
+			return err
+		}
+	} else {
+		keyTarget2, fieldTarget3, err := fieldsTarget1.StartField("Desc")
+		if err != vdl.ErrFieldNoExist {
+			if err != nil {
 				return err
 			}
-		} else {
 			if err := fieldTarget3.FromString(string(m.Desc), tt.NonOptional().Field(0).Type); err != nil {
 				return err
 			}
-		}
-		if err := fieldsTarget1.FinishField(keyTarget2, fieldTarget3); err != nil {
-			return err
-		}
-	}
-	keyTarget5, fieldTarget6, err := fieldsTarget1.StartField("Sampler")
-	if err != vdl.ErrFieldNoExist && err != nil {
-		return err
-	}
-	if err != vdl.ErrFieldNoExist {
-
-		var7 := (m.Sampler == SamplerDef{})
-		if var7 {
-			if err := fieldTarget6.FromZero(tt.NonOptional().Field(1).Type); err != nil {
+			if err := fieldsTarget1.FinishField(keyTarget2, fieldTarget3); err != nil {
 				return err
 			}
-		} else {
+		}
+	}
+	var7 := (m.Sampler == SamplerDef{})
+	if var7 {
+		if err := fieldsTarget1.ZeroField("Sampler"); err != nil && err != vdl.ErrFieldNoExist {
+			return err
+		}
+	} else {
+		keyTarget5, fieldTarget6, err := fieldsTarget1.StartField("Sampler")
+		if err != vdl.ErrFieldNoExist {
+			if err != nil {
+				return err
+			}
 
 			if err := m.Sampler.FillVDLTarget(fieldTarget6, tt.NonOptional().Field(1).Type); err != nil {
 				return err
 			}
-		}
-		if err := fieldsTarget1.FinishField(keyTarget5, fieldTarget6); err != nil {
-			return err
-		}
-	}
-	keyTarget8, fieldTarget9, err := fieldsTarget1.StartField("Enabled")
-	if err != vdl.ErrFieldNoExist && err != nil {
-		return err
-	}
-	if err != vdl.ErrFieldNoExist {
-
-		var10 := (m.Enabled == false)
-		if var10 {
-			if err := fieldTarget9.FromZero(tt.NonOptional().Field(2).Type); err != nil {
+			if err := fieldsTarget1.FinishField(keyTarget5, fieldTarget6); err != nil {
 				return err
 			}
-		} else {
+		}
+	}
+	var10 := (m.Enabled == false)
+	if var10 {
+		if err := fieldsTarget1.ZeroField("Enabled"); err != nil && err != vdl.ErrFieldNoExist {
+			return err
+		}
+	} else {
+		keyTarget8, fieldTarget9, err := fieldsTarget1.StartField("Enabled")
+		if err != vdl.ErrFieldNoExist {
+			if err != nil {
+				return err
+			}
 			if err := fieldTarget9.FromBool(bool(m.Enabled), tt.NonOptional().Field(2).Type); err != nil {
 				return err
 			}
-		}
-		if err := fieldsTarget1.FinishField(keyTarget8, fieldTarget9); err != nil {
-			return err
+			if err := fieldsTarget1.FinishField(keyTarget8, fieldTarget9); err != nil {
+				return err
+			}
 		}
 	}
 	if err := t.FinishFields(fieldsTarget1); err != nil {
@@ -492,14 +519,25 @@
 func (t *VStreamDefTarget) FinishField(_, _ vdl.Target) error {
 	return nil
 }
+func (t *VStreamDefTarget) ZeroField(name string) error {
+	switch name {
+	case "Desc":
+		t.Value.Desc = ""
+		return nil
+	case "Sampler":
+		t.Value.Sampler = SamplerDef{}
+		return nil
+	case "Enabled":
+		t.Value.Enabled = false
+		return nil
+	default:
+		return fmt.Errorf("field %s not in struct v.io/x/sensorlog/internal/sbmodel.VStreamDef", name)
+	}
+}
 func (t *VStreamDefTarget) FinishFields(_ vdl.FieldsTarget) error {
 
 	return nil
 }
-func (t *VStreamDefTarget) FromZero(tt *vdl.Type) error {
-	*t.Value = VStreamDef{}
-	return nil
-}
 
 type KStreamDef struct {
 	DevId    string
@@ -516,44 +554,42 @@
 	if err != nil {
 		return err
 	}
-	keyTarget2, fieldTarget3, err := fieldsTarget1.StartField("DevId")
-	if err != vdl.ErrFieldNoExist && err != nil {
-		return err
-	}
-	if err != vdl.ErrFieldNoExist {
-
-		var4 := (m.DevId == "")
-		if var4 {
-			if err := fieldTarget3.FromZero(tt.NonOptional().Field(0).Type); err != nil {
+	var4 := (m.DevId == "")
+	if var4 {
+		if err := fieldsTarget1.ZeroField("DevId"); err != nil && err != vdl.ErrFieldNoExist {
+			return err
+		}
+	} else {
+		keyTarget2, fieldTarget3, err := fieldsTarget1.StartField("DevId")
+		if err != vdl.ErrFieldNoExist {
+			if err != nil {
 				return err
 			}
-		} else {
 			if err := fieldTarget3.FromString(string(m.DevId), tt.NonOptional().Field(0).Type); err != nil {
 				return err
 			}
-		}
-		if err := fieldsTarget1.FinishField(keyTarget2, fieldTarget3); err != nil {
-			return err
-		}
-	}
-	keyTarget5, fieldTarget6, err := fieldsTarget1.StartField("StreamId")
-	if err != vdl.ErrFieldNoExist && err != nil {
-		return err
-	}
-	if err != vdl.ErrFieldNoExist {
-
-		var7 := (m.StreamId == "")
-		if var7 {
-			if err := fieldTarget6.FromZero(tt.NonOptional().Field(1).Type); err != nil {
+			if err := fieldsTarget1.FinishField(keyTarget2, fieldTarget3); err != nil {
 				return err
 			}
-		} else {
+		}
+	}
+	var7 := (m.StreamId == "")
+	if var7 {
+		if err := fieldsTarget1.ZeroField("StreamId"); err != nil && err != vdl.ErrFieldNoExist {
+			return err
+		}
+	} else {
+		keyTarget5, fieldTarget6, err := fieldsTarget1.StartField("StreamId")
+		if err != vdl.ErrFieldNoExist {
+			if err != nil {
+				return err
+			}
 			if err := fieldTarget6.FromString(string(m.StreamId), tt.NonOptional().Field(1).Type); err != nil {
 				return err
 			}
-		}
-		if err := fieldsTarget1.FinishField(keyTarget5, fieldTarget6); err != nil {
-			return err
+			if err := fieldsTarget1.FinishField(keyTarget5, fieldTarget6); err != nil {
+				return err
+			}
 		}
 	}
 	if err := t.FinishFields(fieldsTarget1); err != nil {
@@ -598,14 +634,22 @@
 func (t *KStreamDefTarget) FinishField(_, _ vdl.Target) error {
 	return nil
 }
+func (t *KStreamDefTarget) ZeroField(name string) error {
+	switch name {
+	case "DevId":
+		t.Value.DevId = ""
+		return nil
+	case "StreamId":
+		t.Value.StreamId = ""
+		return nil
+	default:
+		return fmt.Errorf("field %s not in struct v.io/x/sensorlog/internal/sbmodel.KStreamDef", name)
+	}
+}
 func (t *KStreamDefTarget) FinishFields(_ vdl.FieldsTarget) error {
 
 	return nil
 }
-func (t *KStreamDefTarget) FromZero(tt *vdl.Type) error {
-	*t.Value = KStreamDef{}
-	return nil
-}
 
 // sdata : <DevId>/<StreamId>/<Timestamp>
 // Measured data value or error.
@@ -625,44 +669,42 @@
 	if err != nil {
 		return err
 	}
-	keyTarget2, fieldTarget3, err := fieldsTarget1.StartField("DevId")
-	if err != vdl.ErrFieldNoExist && err != nil {
-		return err
-	}
-	if err != vdl.ErrFieldNoExist {
-
-		var4 := (m.DevId == "")
-		if var4 {
-			if err := fieldTarget3.FromZero(tt.NonOptional().Field(0).Type); err != nil {
+	var4 := (m.DevId == "")
+	if var4 {
+		if err := fieldsTarget1.ZeroField("DevId"); err != nil && err != vdl.ErrFieldNoExist {
+			return err
+		}
+	} else {
+		keyTarget2, fieldTarget3, err := fieldsTarget1.StartField("DevId")
+		if err != vdl.ErrFieldNoExist {
+			if err != nil {
 				return err
 			}
-		} else {
 			if err := fieldTarget3.FromString(string(m.DevId), tt.NonOptional().Field(0).Type); err != nil {
 				return err
 			}
-		}
-		if err := fieldsTarget1.FinishField(keyTarget2, fieldTarget3); err != nil {
-			return err
-		}
-	}
-	keyTarget5, fieldTarget6, err := fieldsTarget1.StartField("StreamId")
-	if err != vdl.ErrFieldNoExist && err != nil {
-		return err
-	}
-	if err != vdl.ErrFieldNoExist {
-
-		var7 := (m.StreamId == "")
-		if var7 {
-			if err := fieldTarget6.FromZero(tt.NonOptional().Field(1).Type); err != nil {
+			if err := fieldsTarget1.FinishField(keyTarget2, fieldTarget3); err != nil {
 				return err
 			}
-		} else {
+		}
+	}
+	var7 := (m.StreamId == "")
+	if var7 {
+		if err := fieldsTarget1.ZeroField("StreamId"); err != nil && err != vdl.ErrFieldNoExist {
+			return err
+		}
+	} else {
+		keyTarget5, fieldTarget6, err := fieldsTarget1.StartField("StreamId")
+		if err != vdl.ErrFieldNoExist {
+			if err != nil {
+				return err
+			}
 			if err := fieldTarget6.FromString(string(m.StreamId), tt.NonOptional().Field(1).Type); err != nil {
 				return err
 			}
-		}
-		if err := fieldsTarget1.FinishField(keyTarget5, fieldTarget6); err != nil {
-			return err
+			if err := fieldsTarget1.FinishField(keyTarget5, fieldTarget6); err != nil {
+				return err
+			}
 		}
 	}
 	var wireValue8 time_2.Time
@@ -670,25 +712,24 @@
 		return err
 	}
 
-	keyTarget9, fieldTarget10, err := fieldsTarget1.StartField("Timestamp")
-	if err != vdl.ErrFieldNoExist && err != nil {
-		return err
-	}
-	if err != vdl.ErrFieldNoExist {
-
-		var11 := (wireValue8 == time_2.Time{})
-		if var11 {
-			if err := fieldTarget10.FromZero(tt.NonOptional().Field(2).Type); err != nil {
+	var11 := (wireValue8 == time_2.Time{})
+	if var11 {
+		if err := fieldsTarget1.ZeroField("Timestamp"); err != nil && err != vdl.ErrFieldNoExist {
+			return err
+		}
+	} else {
+		keyTarget9, fieldTarget10, err := fieldsTarget1.StartField("Timestamp")
+		if err != vdl.ErrFieldNoExist {
+			if err != nil {
 				return err
 			}
-		} else {
 
 			if err := wireValue8.FillVDLTarget(fieldTarget10, tt.NonOptional().Field(2).Type); err != nil {
 				return err
 			}
-		}
-		if err := fieldsTarget1.FinishField(keyTarget9, fieldTarget10); err != nil {
-			return err
+			if err := fieldsTarget1.FinishField(keyTarget9, fieldTarget10); err != nil {
+				return err
+			}
 		}
 	}
 	if err := t.FinishFields(fieldsTarget1); err != nil {
@@ -738,14 +779,31 @@
 func (t *KDataPointTarget) FinishField(_, _ vdl.Target) error {
 	return nil
 }
+func (t *KDataPointTarget) ZeroField(name string) error {
+	switch name {
+	case "DevId":
+		t.Value.DevId = ""
+		return nil
+	case "StreamId":
+		t.Value.StreamId = ""
+		return nil
+	case "Timestamp":
+		t.Value.Timestamp = func() time.Time {
+			var native time.Time
+			if err := vdl.Convert(&native, time_2.Time{}); err != nil {
+				panic(err)
+			}
+			return native
+		}()
+		return nil
+	default:
+		return fmt.Errorf("field %s not in struct v.io/x/sensorlog/internal/sbmodel.KDataPoint", name)
+	}
+}
 func (t *KDataPointTarget) FinishFields(_ vdl.FieldsTarget) error {
 
 	return nil
 }
-func (t *KDataPointTarget) FromZero(tt *vdl.Type) error {
-	*t.Value = KDataPoint{}
-	return nil
-}
 
 type (
 	// VDataPoint represents any single field of the VDataPoint union type.
@@ -879,10 +937,6 @@
 
 	return nil
 }
-func (t *VDataPointTarget) FromZero(tt *vdl.Type) error {
-	*t.Value = VDataPoint(VDataPointValue{})
-	return nil
-}
 
 type vDataPointTargetFactory struct{}