Sometimes, the last seen time is empty

client.go

@@ -237,7 +237,7 @@ func (c *Client) breathe(selector string, breathe Breathe) (*Response, error) {
 	return resp, nil
 }
 
-func (c *Client) setStates(selector string, states States) (*Response, error) {
+func (c *Client) setStates(states States) (*Response, error) {
 	var (
 		err  error
 		j    []byte

color.go

@@ -4,7 +4,6 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"net/http"
 	"strings"
 )
 
@@ -164,6 +163,10 @@ func (c RGBColor) ColorString() string {
 	return fmt.Sprintf("rgb:%d,%d,%d", c.R, c.G, c.B)
 }
 
+func (c RGBColor) String() string {
+	return c.ColorString()
+}
+
 func (c RGBColor) Hex() string {
 	return fmt.Sprintf("#%x%x%x", c.R, c.G, c.B)
 }
@@ -185,6 +188,10 @@ func (c HSBKColor) ColorString() string {
 	return strings.Join(s, " ")
 }
 
+func (c HSBKColor) String() string {
+	return c.ColorString()
+}
+
 func (c HSBKColor) MarshalText() ([]byte, error) {
 	return []byte(c.ColorString()), nil
 }
@@ -197,11 +204,14 @@ func (c NamedColor) ColorString() string {
 	return string(c)
 }
 
+func (c NamedColor) String() string {
+	return c.ColorString()
+}
+
 func (c *Client) ValidateColor(color Color) (Color, error) {
 	var (
 		err  error
 		s    *HSBKColor
-		r    *http.Response
 		resp *Response
 	)
 
@@ -209,13 +219,12 @@ func (c *Client) ValidateColor(color Color) (Color, error) {
 		return nil, err
 	}
 
-	resp, err = NewResponse(r)
-	if err != nil {
-		return nil, err
-	}
-
 	defer resp.Body.Close()
 
+	if resp.IsError() {
+		return nil, resp.GetLifxError()
+	}
+
 	if err = json.NewDecoder(resp.Body).Decode(&s); err != nil {
 		return nil, err
 	}

lights.go

@@ -51,7 +51,7 @@ type (
 		Group           Selector   `json:"group"`
 		Location        Selector   `json:"location"`
 		Product         Product    `json:"product"`
-		LastSeen        time.Time `json:"last_seen"`
+		LastSeen        *time.Time `json:"last_seen,omitempty"`
 		SecondsLastSeen float64    `json:"seconds_last_seen"`
 	}
 
@@ -156,14 +156,14 @@ func (c *Client) FastSetState(selector string, state State) (*LifxResponse, erro
 	return c.SetState(selector, state)
 }
 
-func (c *Client) SetStates(selector string, states States) (*LifxResponse, error) {
+func (c *Client) SetStates(states States) (*LifxResponse, error) {
 	var (
 		err  error
 		s    *LifxResponse
 		resp *Response
 	)
 
-	if resp, err = c.setStates(selector, states); err != nil {
+	if resp, err = c.setStates(states); err != nil {
 		return nil, err
 	}
 	defer resp.Body.Close()