diff --git a/chapter10/listing01/listing01.go b/chapter10/listing01/listing01.go
new file mode 100644
index 0000000..998d91d
--- /dev/null
+++ b/chapter10/listing01/listing01.go
@@ -0,0 +1,116 @@
+// Sample program demonstrating struct composition.
+package main
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"math/rand"
+	"time"
+)
+
+func init() {
+	rand.Seed(time.Now().UnixNano())
+}
+
+// =============================================================================
+
+// Data is the structure of the data we are copying.
+type Data struct {
+	Line string
+}
+
+// =============================================================================
+
+// Xenia is a system we need to pull data from.
+type Xenia struct{}
+
+// Pull knows how to pull data out of Xenia.
+func (Xenia) Pull(d *Data) error {
+	switch rand.Intn(10) {
+	case 1, 9:
+		return io.EOF
+
+	case 5:
+		return errors.New("Error reading data from Xenia")
+
+	default:
+		d.Line = "Data"
+		fmt.Println("In:", d.Line)
+		return nil
+	}
+}
+
+// Pillar is a system we need to store data into.
+type Pillar struct{}
+
+// Store knows how to store data into Pillar.
+func (Pillar) Store(d Data) error {
+	fmt.Println("Out:", d.Line)
+	return nil
+}
+
+// =============================================================================
+
+// System wraps Xenia and Pillar together into a single system.
+type System struct {
+	Xenia
+	Pillar
+}
+
+// =============================================================================
+
+// pull knows how to pull bulks of data from Xenia.
+func pull(x *Xenia, data []Data) (int, error) {
+	for i := range data {
+		if err := x.Pull(&data[i]); err != nil {
+			return i, err
+		}
+	}
+
+	return len(data), nil
+}
+
+// store knows how to store bulks of data into Pillar.
+func store(p *Pillar, data []Data) (int, error) {
+	for i, d := range data {
+		if err := p.Store(d); err != nil {
+			return i, err
+		}
+	}
+
+	return len(data), nil
+}
+
+// Copy knows how to pull and store data from the System.
+func Copy(sys *System, batch int) error {
+	data := make([]Data, batch)
+
+	for {
+		i, err := pull(&sys.Xenia, data)
+		if i > 0 {
+			if _, err := store(&sys.Pillar, data[:i]); err != nil {
+				return err
+			}
+		}
+
+		if err != nil {
+			return err
+		}
+	}
+}
+
+// =============================================================================
+
+func main() {
+
+	// Initialize the system for use.
+	sys := System{
+		Xenia:  Xenia{},
+		Pillar: Pillar{},
+	}
+
+	if err := Copy(&sys, 3); err != io.EOF {
+		fmt.Println(err)
+	}
+}
diff --git a/chapter10/listing02/listing02.go b/chapter10/listing02/listing02.go
new file mode 100644
index 0000000..26c7700
--- /dev/null
+++ b/chapter10/listing02/listing02.go
@@ -0,0 +1,128 @@
+// Sample program demonstrating decoupling with interfaces.
+package main
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"math/rand"
+	"time"
+)
+
+func init() {
+	rand.Seed(time.Now().UnixNano())
+}
+
+// =============================================================================
+
+// Data is the structure of the data we are copying.
+type Data struct {
+	Line string
+}
+
+// =============================================================================
+
+// Puller declares behavior for pulling data.
+type Puller interface {
+	Pull(d *Data) error
+}
+
+// Storer declares behavior for storing data.
+type Storer interface {
+	Store(d Data) error
+}
+
+// =============================================================================
+
+// Xenia is a system we need to pull data from.
+type Xenia struct{}
+
+// Pull knows how to pull data out of Xenia.
+func (Xenia) Pull(d *Data) error {
+	switch rand.Intn(10) {
+	case 1, 9:
+		return io.EOF
+
+	case 5:
+		return errors.New("Error reading data from Xenia")
+
+	default:
+		d.Line = "Data"
+		fmt.Println("In:", d.Line)
+		return nil
+	}
+}
+
+// Pillar is a system we need to store data into.
+type Pillar struct{}
+
+// Store knows how to store data into Pillar.
+func (Pillar) Store(d Data) error {
+	fmt.Println("Out:", d.Line)
+	return nil
+}
+
+// =============================================================================
+
+// System wraps Xenia and Pillar together into a single system.
+type System struct {
+	Xenia
+	Pillar
+}
+
+// =============================================================================
+
+// pull knows how to pull bulks of data from any Puller.
+func pull(p Puller, data []Data) (int, error) {
+	for i := range data {
+		if err := p.Pull(&data[i]); err != nil {
+			return i, err
+		}
+	}
+
+	return len(data), nil
+}
+
+// store knows how to store bulks of data from any Storer.
+func store(s Storer, data []Data) (int, error) {
+	for i, d := range data {
+		if err := s.Store(d); err != nil {
+			return i, err
+		}
+	}
+
+	return len(data), nil
+}
+
+// Copy knows how to pull and store data from the System.
+func Copy(sys *System, batch int) error {
+	data := make([]Data, batch)
+
+	for {
+		i, err := pull(&sys.Xenia, data)
+		if i > 0 {
+			if _, err := store(&sys.Pillar, data[:i]); err != nil {
+				return err
+			}
+		}
+
+		if err != nil {
+			return err
+		}
+	}
+}
+
+// =============================================================================
+
+func main() {
+
+	// Initialize the system for use.
+	sys := System{
+		Xenia:  Xenia{},
+		Pillar: Pillar{},
+	}
+
+	if err := Copy(&sys, 3); err != io.EOF {
+		fmt.Println(err)
+	}
+}
diff --git a/chapter10/listing03/listing03.go b/chapter10/listing03/listing03.go
new file mode 100644
index 0000000..a05e57b
--- /dev/null
+++ b/chapter10/listing03/listing03.go
@@ -0,0 +1,134 @@
+// Sample program demonstrating interface composition.
+package main
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"math/rand"
+	"time"
+)
+
+func init() {
+	rand.Seed(time.Now().UnixNano())
+}
+
+// =============================================================================
+
+// Data is the structure of the data we are copying.
+type Data struct {
+	Line string
+}
+
+// =============================================================================
+
+// Puller declares behavior for pulling data.
+type Puller interface {
+	Pull(d *Data) error
+}
+
+// Storer declares behavior for storing data.
+type Storer interface {
+	Store(d Data) error
+}
+
+// PullStorer declares behavior for both pulling and storing.
+type PullStorer interface {
+	Puller
+	Storer
+}
+
+// =============================================================================
+
+// Xenia is a system we need to pull data from.
+type Xenia struct{}
+
+// Pull knows how to pull data out of Xenia.
+func (Xenia) Pull(d *Data) error {
+	switch rand.Intn(10) {
+	case 1, 9:
+		return io.EOF
+
+	case 5:
+		return errors.New("Error reading data from Xenia")
+
+	default:
+		d.Line = "Data"
+		fmt.Println("In:", d.Line)
+		return nil
+	}
+}
+
+// Pillar is a system we need to store data into.
+type Pillar struct{}
+
+// Store knows how to store data into Pillar.
+func (Pillar) Store(d Data) error {
+	fmt.Println("Out:", d.Line)
+	return nil
+}
+
+// =============================================================================
+
+// System wraps Xenia and Pillar together into a single system.
+type System struct {
+	Xenia
+	Pillar
+}
+
+// =============================================================================
+
+// pull knows how to pull bulks of data from any Puller.
+func pull(p Puller, data []Data) (int, error) {
+	for i := range data {
+		if err := p.Pull(&data[i]); err != nil {
+			return i, err
+		}
+	}
+
+	return len(data), nil
+}
+
+// store knows how to store bulks of data from any Storer.
+func store(s Storer, data []Data) (int, error) {
+	for i, d := range data {
+		if err := s.Store(d); err != nil {
+			return i, err
+		}
+	}
+
+	return len(data), nil
+}
+
+// Copy knows how to pull and store data from any System.
+func Copy(ps PullStorer, batch int) error {
+	data := make([]Data, batch)
+
+	for {
+		i, err := pull(ps, data)
+		if i > 0 {
+			if _, err := store(ps, data[:i]); err != nil {
+				return err
+			}
+		}
+
+		if err != nil {
+			return err
+		}
+	}
+}
+
+// =============================================================================
+
+func main() {
+
+	// Initialize the system for use.
+	sys := System{
+		Xenia:  Xenia{},
+		Pillar: Pillar{},
+	}
+
+	if err := Copy(&sys, 3); err != io.EOF {
+		fmt.Println(err)
+	}
+}
diff --git a/chapter10/listing04/listing04.go b/chapter10/listing04/listing04.go
new file mode 100644
index 0000000..b5b1145
--- /dev/null
+++ b/chapter10/listing04/listing04.go
@@ -0,0 +1,134 @@
+// Sample program demonstrating decoupling with interface composition.
+package main
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"math/rand"
+	"time"
+)
+
+func init() {
+	rand.Seed(time.Now().UnixNano())
+}
+
+// =============================================================================
+
+// Data is the structure of the data we are copying.
+type Data struct {
+	Line string
+}
+
+// =============================================================================
+
+// Puller declares behavior for pulling data.
+type Puller interface {
+	Pull(d *Data) error
+}
+
+// Storer declares behavior for storing data.
+type Storer interface {
+	Store(d Data) error
+}
+
+// PullStorer declares behavior for both pulling and storing.
+type PullStorer interface {
+	Puller
+	Storer
+}
+
+// =============================================================================
+
+// Xenia is a system we need to pull data from.
+type Xenia struct{}
+
+// Pull knows how to pull data out of Xenia.
+func (Xenia) Pull(d *Data) error {
+	switch rand.Intn(10) {
+	case 1, 9:
+		return io.EOF
+
+	case 5:
+		return errors.New("Error reading data from Xenia")
+
+	default:
+		d.Line = "Data"
+		fmt.Println("In:", d.Line)
+		return nil
+	}
+}
+
+// Pillar is a system we need to store data into.
+type Pillar struct{}
+
+// Store knows how to store data into Pillar.
+func (Pillar) Store(d Data) error {
+	fmt.Println("Out:", d.Line)
+	return nil
+}
+
+// =============================================================================
+
+// System wraps Pullers and Stores together into a single system.
+type System struct {
+	Puller
+	Storer
+}
+
+// =============================================================================
+
+// pull knows how to pull bulks of data from any Puller.
+func pull(p Puller, data []Data) (int, error) {
+	for i := range data {
+		if err := p.Pull(&data[i]); err != nil {
+			return i, err
+		}
+	}
+
+	return len(data), nil
+}
+
+// store knows how to store bulks of data from any Storer.
+func store(s Storer, data []Data) (int, error) {
+	for i, d := range data {
+		if err := s.Store(d); err != nil {
+			return i, err
+		}
+	}
+
+	return len(data), nil
+}
+
+// Copy knows how to pull and store data from any System.
+func Copy(ps PullStorer, batch int) error {
+	data := make([]Data, batch)
+
+	for {
+		i, err := pull(ps, data)
+		if i > 0 {
+			if _, err := store(ps, data[:i]); err != nil {
+				return err
+			}
+		}
+
+		if err != nil {
+			return err
+		}
+	}
+}
+
+// =============================================================================
+
+func main() {
+
+	// Initialize the system for use.
+	sys := System{
+		Puller: Xenia{},
+		Storer: Pillar{},
+	}
+
+	if err := Copy(&sys, 3); err != io.EOF {
+		fmt.Println(err)
+	}
+}
diff --git a/chapter10/listing05/listing05.go b/chapter10/listing05/listing05.go
new file mode 100644
index 0000000..dd358d5
--- /dev/null
+++ b/chapter10/listing05/listing05.go
@@ -0,0 +1,81 @@
+// Sample program demonstrating when implicit interface conversions
+// are provided by the compiler.
+package main
+
+import "fmt"
+
+// =============================================================================
+
+// Mover provides support for moving things.
+type Mover interface {
+	Move()
+}
+
+// Locker provides support for locking and unlocking things.
+type Locker interface {
+	Lock()
+	Unlock()
+}
+
+// MoveLocker provides support for moving and locking things.
+type MoveLocker interface {
+	Mover
+	Locker
+}
+
+// =============================================================================
+
+// bike represents a concrete type for the example.
+type bike struct{}
+
+// Move can change the position of a bike.
+func (bike) Move() {
+	fmt.Println("Moving the bike")
+}
+
+// Lock prevents a bike from moving.
+func (bike) Lock() {
+	fmt.Println("Locking the bike")
+}
+
+// Unlock allows a bike to be moved.
+func (bike) Unlock() {
+	fmt.Println("Unlocking the bike")
+}
+
+// =============================================================================
+
+func main() {
+
+	// Declare variables of the MoveLocker and Mover interfaces set to their
+	// zero value.
+	var ml MoveLocker
+	var m Mover
+
+	// Create a value of type bike and assign the value to the MoveLocker
+	// interface value.
+	ml = bike{}
+
+	// An interface value of type MoveLocker can be implicitly converted into
+	// a value of type Mover. They both declare a method named move.
+	m = ml
+
+	// prog.go:65: cannot use m (type Mover) as type MoveLocker in assignment:
+	//	   Mover does not implement MoveLocker (missing Lock method)
+	ml = m
+
+	// Interface type Mover does not declare methods named lock and unlock.
+	// Therefore, the compiler can't perform an implicit conversion to assign
+	// a value of interface type Mover to an interface value of type MoveLocker.
+	// It is irrelevant that the concrete type value of type bike that is stored
+	// inside of the Mover interface value implements the MoveLocker interface.
+
+	// We can perform a type assertion at runtime to support the assignment.
+
+	// Perform a type assertion against the Mover interface value to access
+	// a COPY of the concrete type value of type bike that was stored inside
+	// of it. Then assign the COPY of the concrete type to the MoveLocker
+	// interface.
+	b := m.(bike)
+	ml = b
+}
diff --git a/chapter10/listing06/listing06 b/chapter10/listing06/listing06
new file mode 100755
index 0000000..e927805
Binary files /dev/null and b/chapter10/listing06/listing06 differ
diff --git a/chapter10/listing06/listing06.go b/chapter10/listing06/listing06.go
new file mode 100644
index 0000000..f728ab4
--- /dev/null
+++ b/chapter10/listing06/listing06.go
@@ -0,0 +1,51 @@
+// Sample program to show how you can personally mock concrete types when
+// you need to for your own packages or tests.
+package main
+
+import (
+	"github.com/goinaction/code/chapter10/listing06/pubsub"
+)
+
+// publisher is an interface to allow this package to mock the
+// pubsub package support.
+type publisher interface {
+	Publish(key string, v interface{}) error
+	Subscribe(key string) error
+}
+
+// mock is a concrete type to help support the mocking of the
+// pubsub package.
+type mock struct{}
+
+// Publish implements the publisher interface for the mock.
+func (m *mock) Publish(key string, v interface{}) error {
+
+	// ADD YOUR MOCK FOR THE PUBLISH CALL.
+	return nil
+}
+
+// Subscribe implements the publisher interface for the mock.
+func (m *mock) Subscribe(key string) error {
+
+	// ADD YOUR MOCK FOR THE SUBSCRIBE CALL.
+	return nil
+}
+
+func main() {
+
+	// Create a slice of publisher interface values. Assign
+	// the address of a pubsub.PubSub value and the address of
+	// a mock value.
+	pubs := []publisher{
+		pubsub.New("localhost"),
+		&mock{},
+	}
+
+	// Range over the interface value to see how the publisher
+	// interface provides the level of decoupling the user needs.
+	// The pubsub package did not need to provide the interface type.
+	for _, p := range pubs {
+		p.Publish("key", "value")
+		p.Subscribe("key")
+	}
+}
diff --git a/chapter10/listing06/pubsub/pubsub.go b/chapter10/listing06/pubsub/pubsub.go
new file mode 100644
index 0000000..9b6c7a5
--- /dev/null
+++ b/chapter10/listing06/pubsub/pubsub.go
@@ -0,0 +1,36 @@
+// Package pubsub simulates a package that provides
+// publication/subscription type services.
+package pubsub
+
+// PubSub provides access to a queue system.
+type PubSub struct {
+	host string
+
+	// PRETEND THERE ARE MORE FIELDS.
+}
+
+// New creates a pubsub value for use.
+func New(host string) *PubSub {
+	ps := PubSub{
+		host: host,
+	}
+
+	// PRETEND THERE IS A SPECIFIC IMPLEMENTATION.
+
+	return &ps
+}
+
+// Publish sends the data for the specified key.
+func (ps *PubSub) Publish(key string, v interface{}) error {
+
+	// PRETEND THERE IS A SPECIFIC IMPLEMENTATION.
+	return nil
+}
+
+// Subscribe sets up an request to receive messages for the
+// specified key.
+func (ps *PubSub) Subscribe(key string) error {
+
+	// PRETEND THERE IS A SPECIFIC IMPLEMENTATION.
+	return nil
+}
diff --git a/chapter2/sample/data/data.json b/chapter2/sample/data/data.json
index d1922e7..cf8fc59 100644
--- a/chapter2/sample/data/data.json
+++ b/chapter2/sample/data/data.json
@@ -135,7 +135,7 @@
 	"type" : "rss"
 },
 {
-	"site" : "foxnews",
+	"site" : "cnn",
 	"link" : "http://rss.cnn.com/rss/cnn_topstories.rss",
 	"type" : "rss"
 },