diff --git a/src/main/java/org/ultramine/permission/GroupPermission.java b/src/main/java/org/ultramine/permission/GroupPermission.java
index 4704f86..943025f 100644
--- a/src/main/java/org/ultramine/permission/GroupPermission.java
+++ b/src/main/java/org/ultramine/permission/GroupPermission.java
@@ -3,14 +3,15 @@
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
-import java.util.*;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
 
-/**
- * Created by Евгений on 08.05.2014.
- */
+
 public class GroupPermission extends MetaHolder implements IChangeablePermission, IDirtyListener
 {
-	private static Logger logger = LogManager.getLogger();
+	private static Logger logger = LogManager.getLogger(GroupPermission.class);
 
 	private String key;
 	private boolean dirty;
@@ -83,7 +84,7 @@
 
 		permissions.put(permission.getKey(), permission);
 		if (permission instanceof IChangeablePermission)
-			((IChangeablePermission)permission).subscribe(this);
+			((IChangeablePermission) permission).subscribe(this);
 
 		makeDirty();
 	}
@@ -100,7 +101,7 @@
 
 		IPermission perm = permissions.remove(key);
 		if (perm instanceof IChangeablePermission)
-			((IChangeablePermission)perm).unsubscribe(this);
+			((IChangeablePermission) perm).unsubscribe(this);
 
 		makeDirty();
 	}
@@ -126,6 +127,7 @@
 	@Override
 	public void makeDirty()
 	{
+		logger.error(getName());
 		if (isDirty())
 			return;
 
@@ -148,31 +150,22 @@
 		makeDirty();
 	}
 
-	public void calculate() throws RecursiveCalculationException
+	public void calculate()
 	{
 		if (!isDirty())
 			return;
+		dirty = false;
 
 		permissionResolver.clear();
 		metaResolver.clear();
 
-		try
+		for (IPermission permission : permissions.values())
 		{
-			for (IPermission permission : permissions.values())
-			{
-				permissionResolver.merge(permission.getPermissions(), permission.getPriority());
-				metaResolver.merge(permission.getMeta(), permission.getPriority());
-			}
+			permissionResolver.merge(permission.getPermissions(), permission.getPriority());
+			metaResolver.merge(permission.getMeta(), permission.getPriority());
 		}
-		catch (StackOverflowError ignored)
-		{
-			throw new RecursiveCalculationException(this);
-		}
-		finally
-		{
-			metaResolver.merge(innerMeta, Integer.MAX_VALUE);
-			dirty = false;
-		}
+
+		metaResolver.merge(innerMeta, Integer.MAX_VALUE);
 	}
 
 	@Override
@@ -185,7 +178,7 @@
 	public boolean equals(Object obj)
 	{
 		if (obj instanceof IPermission)
-			return getKey().equals(((IPermission)obj).getKey());
+			return getKey().equals(((IPermission) obj).getKey());
 
 		return super.equals(obj);
 	}
diff --git a/src/main/java/org/ultramine/permission/IChangeablePermission.java b/src/main/java/org/ultramine/permission/IChangeablePermission.java
index a79f0da..2b8bc5a 100644
--- a/src/main/java/org/ultramine/permission/IChangeablePermission.java
+++ b/src/main/java/org/ultramine/permission/IChangeablePermission.java
@@ -1,10 +1,5 @@
 package org.ultramine.permission;
 
-import java.util.Map;
-
-/**
- * Created by Евгений on 07.05.2014.
- */
 public interface IChangeablePermission extends IPermission
 {
 	public boolean isDirty();
diff --git a/src/main/java/org/ultramine/permission/IDirtyListener.java b/src/main/java/org/ultramine/permission/IDirtyListener.java
index 4aff430..349785b 100644
--- a/src/main/java/org/ultramine/permission/IDirtyListener.java
+++ b/src/main/java/org/ultramine/permission/IDirtyListener.java
@@ -1,8 +1,5 @@
 package org.ultramine.permission;
 
-/**
- * Created by Евгений on 07.05.2014.
- */
 public interface IDirtyListener
 {
 	public void makeDirty();
diff --git a/src/main/java/org/ultramine/permission/IPermission.java b/src/main/java/org/ultramine/permission/IPermission.java
index a1e551b..4179247 100644
--- a/src/main/java/org/ultramine/permission/IPermission.java
+++ b/src/main/java/org/ultramine/permission/IPermission.java
@@ -1,8 +1,5 @@
 package org.ultramine.permission;
 
-/**
- * Created by Евгений on 02.05.2014.
- */
 public interface IPermission
 {
 	public String getKey();
diff --git a/src/main/java/org/ultramine/permission/MetaHolder.java b/src/main/java/org/ultramine/permission/MetaHolder.java
index 7e92981..e8480c3 100644
--- a/src/main/java/org/ultramine/permission/MetaHolder.java
+++ b/src/main/java/org/ultramine/permission/MetaHolder.java
@@ -3,9 +3,6 @@
 import java.util.HashMap;
 import java.util.Map;
 
-/**
- * Created by Евгений on 08.05.2014.
- */
 public abstract class MetaHolder
 {
 	protected Map<String, Object> innerMeta;
diff --git a/src/main/java/org/ultramine/permission/MetaResolver.java b/src/main/java/org/ultramine/permission/MetaResolver.java
index 1388c97..73836da 100644
--- a/src/main/java/org/ultramine/permission/MetaResolver.java
+++ b/src/main/java/org/ultramine/permission/MetaResolver.java
@@ -1,8 +1,5 @@
 package org.ultramine.permission;
 
-/**
- * Created by uguuseha on 08.05.14.
- */
 public class MetaResolver extends Resolver<Object>
 {
 	public static final MetaResolver BLANK_RESOLVER = new MetaResolver();
diff --git a/src/main/java/org/ultramine/permission/NegativePermission.java b/src/main/java/org/ultramine/permission/NegativePermission.java
index 0b72ec9..0aaeed1 100644
--- a/src/main/java/org/ultramine/permission/NegativePermission.java
+++ b/src/main/java/org/ultramine/permission/NegativePermission.java
@@ -1,8 +1,5 @@
 package org.ultramine.permission;
 
-/**
- * Created by Евгений on 07.05.2014.
- */
 public class NegativePermission implements IChangeablePermission
 {
 	private IPermission permission;
diff --git a/src/main/java/org/ultramine/permission/Permission.java b/src/main/java/org/ultramine/permission/Permission.java
index 98d1142..f4be49f 100644
--- a/src/main/java/org/ultramine/permission/Permission.java
+++ b/src/main/java/org/ultramine/permission/Permission.java
@@ -1,8 +1,5 @@
 package org.ultramine.permission;
 
-/**
- * Created by Евгений on 07.05.2014.
- */
 public class Permission implements IPermission
 {
 	private String key;
diff --git a/src/main/java/org/ultramine/permission/PermissionRepository.java b/src/main/java/org/ultramine/permission/PermissionRepository.java
index 3989c31..f04de7b 100644
--- a/src/main/java/org/ultramine/permission/PermissionRepository.java
+++ b/src/main/java/org/ultramine/permission/PermissionRepository.java
@@ -5,9 +5,6 @@
 import java.util.List;
 import java.util.Map;
 
-/**
- * Created by Евгений on 08.05.2014.
- */
 public class PermissionRepository
 {
 	private Map<String, IPermission> permissions = new HashMap<String, IPermission>();
diff --git a/src/main/java/org/ultramine/permission/PermissionResolver.java b/src/main/java/org/ultramine/permission/PermissionResolver.java
index 8e3ea52..d9aeb3e 100644
--- a/src/main/java/org/ultramine/permission/PermissionResolver.java
+++ b/src/main/java/org/ultramine/permission/PermissionResolver.java
@@ -2,9 +2,6 @@
 
 import java.util.Map;
 
-/**
- * Created by Евгений on 07.05.2014.
- */
 public class PermissionResolver extends Resolver<Boolean>
 {
 	public static PermissionResolver createInverted(PermissionResolver anotherResolver)
diff --git a/src/main/java/org/ultramine/permission/RecursiveCalculationException.java b/src/main/java/org/ultramine/permission/RecursiveCalculationException.java
index a218b9c..00a70f6 100644
--- a/src/main/java/org/ultramine/permission/RecursiveCalculationException.java
+++ b/src/main/java/org/ultramine/permission/RecursiveCalculationException.java
@@ -1,8 +1,5 @@
 package org.ultramine.permission;
 
-/**
- * Created by uguuseha on 08.05.14.
- */
 public class RecursiveCalculationException extends RuntimeException
 {
 	public RecursiveCalculationException(String location)
diff --git a/src/main/java/org/ultramine/permission/Resolver.java b/src/main/java/org/ultramine/permission/Resolver.java
index fe1e834..48b3b21 100644
--- a/src/main/java/org/ultramine/permission/Resolver.java
+++ b/src/main/java/org/ultramine/permission/Resolver.java
@@ -1,16 +1,14 @@
 package org.ultramine.permission;
 
-import java.util.Collection;
+import gnu.trove.map.hash.TObjectIntHashMap;
+
 import java.util.HashMap;
 import java.util.Map;
 
-/**
- * Created by uguuseha on 08.05.14.
- */
 public class Resolver<T>
 {
 	protected Map<String, T> values = new HashMap<String, T>();
-	protected Map<String, Integer> priorities = new HashMap<String, Integer>();
+	protected TObjectIntHashMap<String> priorities = new TObjectIntHashMap<String>();
 
 	public void clear()
 	{
diff --git a/src/test/groovy/org/ultramine/permission/GroupPermissionTest.groovy b/src/test/groovy/org/ultramine/permission/GroupPermissionTest.groovy
index 6ca47d0..b69863c 100644
--- a/src/test/groovy/org/ultramine/permission/GroupPermissionTest.groovy
+++ b/src/test/groovy/org/ultramine/permission/GroupPermissionTest.groovy
@@ -62,7 +62,6 @@
 
     def "Test recursive calculation"() {
         setup: "Prepare recursive groups"
-        def logger = Mock(Logger)
         def group1 = new GroupPermission("g1", [m1: "a"])
         def group2 = new GroupPermission("g2", [m2: "b"])
         group1.addPermission(group2)
@@ -71,20 +70,13 @@
         when: "Calculate permissions"
         group1.calculate()
 
-        then: "Recursive calculation is logged"
-        thrown(RecursiveCalculationException)
-
-        and: "Both groups are not dirty"
+        then: "Both groups are not dirty"
         !group1.isDirty()
         !group2.isDirty()
 
-        and: "Both groups are calculated"
+        and: "Both groups have own meta"
         group1.getMeta().getString("m1")
-        group1.getMeta().getString("m2")
-
-        group2.getMeta().getString("m1")
         group2.getMeta().getString("m2")
-
     }
 
     def "Test dirty notification"() {