diff --git a/impl/echo.go b/impl/echo.go
index 4b294fa..61df394 100644
--- a/impl/echo.go
+++ b/impl/echo.go
@@ -4,7 +4,7 @@ package impl
 // Comes handy when you need to mock a unit
 func Echo() *Impl {
 	return &Impl{
-		Call: func(data []byte) (resp []byte, err error) {
+		actor: func(data []byte) (resp []byte, err error) {
 			return data, nil
 		},
 	}
diff --git a/impl/impl.go b/impl/impl.go
index 5977dfa..d458ca3 100644
--- a/impl/impl.go
+++ b/impl/impl.go
@@ -2,14 +2,10 @@ package impl
 
 type (
 	Impl struct {
-		Call func([]byte) ([]byte, error)
+		actor func([]byte) ([]byte, error)
 	}
 )
 
-func (i *Impl) Units() []string {
-	return []string{}
-}
-
 func New(name string) *Impl {
 	switch name {
 	case "units.throttler.Throttler":
@@ -18,3 +14,11 @@ func New(name string) *Impl {
 		return nil
 	}
 }
+
+func (i *Impl) Call(data []byte) (resp []byte, err error) {
+	return i.actor(data)
+}
+
+func (i *Impl) Units() []string {
+	return []string{}
+}
diff --git a/impl/throttler.go b/impl/throttler.go
index 2db974f..ed94fa3 100644
--- a/impl/throttler.go
+++ b/impl/throttler.go
@@ -2,7 +2,7 @@ package impl
 
 func Throttler() *Impl {
 	return &Impl{
-		Call: func(data []byte) (resp []byte, err error) {
+		actor: func(data []byte) (resp []byte, err error) {
 			return data, nil
 		},
 	}