Add Twitter::Place#contained_within and Twitter::Place#contained_within?

lib/twitter/place.rb

@@ -16,6 +16,16 @@ def bounding_box?
       !bounding_box.nil?
     end
 
+    def contained_within
+      new_or_null_object(Twitter::Place, :contained_within)
+    end
+
+    # @return [Boolean]
+    def contained_within?
+      !contained_within.nil?
+    end
+    alias contained? contained_within?
+
     # @return [String]
     def country_code
       @country_code ||= @attrs[:country_code] || @attrs[:countryCode]

spec/twitter/place_spec.rb

@@ -21,7 +21,7 @@
   end
 
   describe "#bounding_box" do
-    it "returns a Twitter::Place when bounding_box is set" do
+    it "returns a Twitter::Geo when bounding_box is set" do
       place = Twitter::Place.new(:id => "247f43d441defc03", :bounding_box => {:type => "Polygon", :coordinates => [[[-122.40348192, 37.77752898], [-122.387436, 37.77752898], [-122.387436, 37.79448597], [-122.40348192, 37.79448597]]]})
       expect(place.bounding_box).to be_a Twitter::Geo::Polygon
     end
@@ -42,6 +42,28 @@
     end
   end
 
+  describe "#contained_within" do
+    it "returns a Twitter::Place when contained_within is set" do
+      place = Twitter::Place.new(:id => "247f43d441defc03", :contained_within => {:id => "247f43d441defc04"})
+      expect(place.contained_within).to be_a Twitter::Place
+    end
+    it "returns nil when not contained_within is not set" do
+      place = Twitter::Place.new(:id => "247f43d441defc03")
+      expect(place.contained_within).to be_nil
+    end
+  end
+
+  describe "#contained_within?" do
+    it "returns true when contained_within is set" do
+      place = Twitter::Place.new(:id => "247f43d441defc03", :contained_within => {:id => "247f43d441defc04"})
+      expect(place.contained?).to be_true
+    end
+    it "returns false when contained_within is not set" do
+      place = Twitter::Place.new(:id => "247f43d441defc03")
+      expect(place.contained?).to be_false
+    end
+  end
+
   describe "#country_code" do
     it "returns a country code when set with country_code" do
       place = Twitter::Place.new(:id => "247f43d441defc03", :country_code => "US")