diff --git a/lockable_test.go b/lockable_test.go
index 11e6340..787448f 100644
--- a/lockable_test.go
+++ b/lockable_test.go
@@ -10,7 +10,7 @@ const TestLockableType = NodeType("TEST_LOCKABLE")
 func lockableTestContext(t *testing.T, logs []string) *Context {
   ctx := logTestContext(t, logs)
 
-  err := ctx.RegisterNodeType(TestLockableType, []ExtType{ACLExtType, LockableExtType, ListenerExtType})
+  err := ctx.RegisterNodeType(TestLockableType, []ExtType{ACLExtType, LockableExtType})
   fatalErr(t, err)
 
   return ctx
@@ -54,7 +54,15 @@ func TestLink(t *testing.T) {
 func TestLink10K(t *testing.T) {
   ctx := lockableTestContext(t, []string{"test"})
 
-  NewLockable := func()(*Node, *ListenerExt) {
+  NewLockable := func()(*Node) {
+    l := NewNode(ctx, RandID(), TestLockableType, nil,
+                  NewACLExt(lock_policy, link_policy),
+                  NewLockableExt(),
+                )
+    return l
+  }
+
+  NewListener := func()(*Node, *ListenerExt) {
     listener := NewListenerExt(100000)
     l := NewNode(ctx, RandID(), TestLockableType, nil,
                   listener,
@@ -63,21 +71,22 @@ func TestLink10K(t *testing.T) {
                 )
     return l, listener
   }
-  l0, l0_listener := NewLockable()
+
+  l0, l0_listener := NewListener()
   lockables := make([]*Node, 10000)
   for i, _ := range(lockables) {
-    lockables[i], _ = NewLockable()
+    lockables[i] = NewLockable()
     LinkRequirement(ctx, l0.ID, lockables[i].ID)
   }
 
-  ctx.Log.Logf("test", "CREATED_10K %d")
+  ctx.Log.Logf("test", "CREATED_10K")
 
 
   for i, _ := range(lockables) {
     (*GraphTester)(t).WaitForState(ctx, l0_listener, LinkSignalType, "linked_as_req", time.Millisecond*1000, fmt.Sprintf("No linked_as_req for %d", i))
   }
 
-  ctx.Log.Logf("test", "LINKED_10K: %d")
+  ctx.Log.Logf("test", "LINKED_10K")
 }
 
 func TestLock(t *testing.T) {
diff --git a/node.go b/node.go
index 17360cb..5c2ea3c 100644
--- a/node.go
+++ b/node.go
@@ -12,6 +12,22 @@ import (
   "sync/atomic"
 )
 
+const (
+  // Size of node message channels
+  NODE_MSG_CHAN_DEFAULT = 1024
+  // Magic first four bytes of serialized DB content, stored big endian
+  NODE_DB_MAGIC = 0x2491df14
+  // Total length of the node database header, has magic to verify and type_hash to map to load function
+  NODE_DB_HEADER_LEN = 20
+  EXTENSION_DB_HEADER_LEN = 16
+)
+
+var (
+  // Base NodeID, used as a special value
+  ZeroUUID = uuid.UUID{}
+  ZeroID = NodeID(ZeroUUID)
+)
+
 // A NodeID uniquely identifies a Node
 type NodeID uuid.UUID
 func (id NodeID) MarshalJSON() ([]byte, error) {
@@ -29,10 +45,6 @@ func (id *NodeID) UnmarshalJSON(bytes []byte) error {
   return err
 }
 
-// Base NodeID, used as a special value
-var ZeroUUID = uuid.UUID{}
-var ZeroID = NodeID(ZeroUUID)
-
 func (id NodeID) Serialize() []byte {
   ser, _ := (uuid.UUID)(id).MarshalBinary()
   return ser
@@ -83,7 +95,6 @@ type QueuedSignal struct {
 }
 
 // Default message channel size for nodes
-const NODE_MSG_CHAN_DEFAULT = 1024
 // Nodes represent a group of extensions that can be collectively addressed
 type Node struct {
   ID NodeID
@@ -365,10 +376,6 @@ func Allowed(ctx *Context, principal_id NodeID, action Action, node *Node) error
   return err
 }
 
-// Magic first four bytes of serialized DB content, stored big endian
-const NODE_DB_MAGIC = 0x2491df14
-// Total length of the node database header, has magic to verify and type_hash to map to load function
-const NODE_DB_HEADER_LEN = 20
 // A DBHeader is parsed from the first NODE_DB_HEADER_LEN bytes of a serialized DB node
 type NodeDBHeader struct {
   Magic uint32
@@ -473,7 +480,6 @@ func (extension ExtensionDB) Serialize() []byte {
   return append(header_bytes, extension.Data...)
 }
 
-const EXTENSION_DB_HEADER_LEN = 16
 type ExtensionDBHeader struct {
   TypeHash uint64
   Length uint64