Interface implementation assertions moved outside the functions

stacks/arraystack/arraystack.go

@@ -16,9 +16,8 @@ import (
 	"strings"
 )
 
-func assertStackImplementation() {
-	var _ stacks.Stack = (*Stack)(nil)
-}
+// Assert Stack implementation
+var _ stacks.Stack = (*Stack)(nil)
 
 // Stack holds elements in an array-list
 type Stack struct {

stacks/arraystack/iterator.go

@@ -6,9 +6,8 @@ package arraystack
 
 import "github.com/emirpasic/gods/containers"
 
-func assertIteratorImplementation() {
-	var _ containers.ReverseIteratorWithIndex = (*Iterator)(nil)
-}
+// Assert Iterator implementation
+var _ containers.ReverseIteratorWithIndex = (*Iterator)(nil)
 
 // Iterator returns a stateful iterator whose values can be fetched by an index.
 type Iterator struct {

stacks/arraystack/serialization.go

@@ -8,10 +8,9 @@ import (
 	"github.com/emirpasic/gods/containers"
 )
 
-func assertSerializationImplementation() {
-	var _ containers.JSONSerializer = (*Stack)(nil)
-	var _ containers.JSONDeserializer = (*Stack)(nil)
-}
+// Assert Serialization implementation
+var _ containers.JSONSerializer = (*Stack)(nil)
+var _ containers.JSONDeserializer = (*Stack)(nil)
 
 // ToJSON outputs the JSON representation of the stack.
 func (stack *Stack) ToJSON() ([]byte, error) {