fix: coding style and file format for chapter 11, 12, 13, 14 and 15.

eBook/exercises/chapter_11/simple_interface.go

@@ -1,34 +1,35 @@
-// simple_interface.go
-package main
-
-import (
-	"fmt"
-)
-
-type Simpler interface {
-	Get() int
-	Put(int)
-}
-
-type Simple struct {
-	i int
-}
-
-func (p *Simple) Get() int {
-	return p.i
-}
-
-func (p *Simple) Put(u int) {
-	p.i = u
-}
-
-func fI(it Simpler) int {
-	it.Put(5)
-	return it.Get()
-}
-
-func main() {
-	var s Simple
-	fmt.Println(fI(&s))  // &s is required because Get() is defined with a receiver type pointer
-}
-// Output: 5
+// simple_interface.go
+package main
+
+import (
+	"fmt"
+)
+
+type Simpler interface {
+	Get() int
+	Put(int)
+}
+
+type Simple struct {
+	i int
+}
+
+func (p *Simple) Get() int {
+	return p.i
+}
+
+func (p *Simple) Put(u int) {
+	p.i = u
+}
+
+func fI(it Simpler) int {
+	it.Put(5)
+	return it.Get()
+}
+
+func main() {
+	var s Simple
+	fmt.Println(fI(&s)) // &s is required because Get() is defined with a receiver type pointer
+}
+
+// Output: 5