diff --git a/src/main/java/ru/touchin/roboswag/core/log/ConsoleLogProcessor.java b/src/main/java/ru/touchin/roboswag/core/log/ConsoleLogProcessor.java
index 228b827..04af630 100644
--- a/src/main/java/ru/touchin/roboswag/core/log/ConsoleLogProcessor.java
+++ b/src/main/java/ru/touchin/roboswag/core/log/ConsoleLogProcessor.java
@@ -35,6 +35,7 @@ public class ConsoleLogProcessor extends LogProcessor {
         super(lclevel);
     }
 
+    @NonNull
     private String normalize(@NonNull final String message) {
         return message.replace("\r\n", "\n").replace("\0", "");
     }
diff --git a/src/main/java/ru/touchin/roboswag/core/log/Lc.java b/src/main/java/ru/touchin/roboswag/core/log/Lc.java
index d3f25d1..8ac2c6c 100644
--- a/src/main/java/ru/touchin/roboswag/core/log/Lc.java
+++ b/src/main/java/ru/touchin/roboswag/core/log/Lc.java
@@ -45,12 +45,12 @@ public final class Lc {
 
     public static final LcGroup GENERAL_LC_GROUP = new LcGroup("GENERAL");
 
+    public static final int STACK_TRACE_CODE_DEPTH;
+
     private static boolean crashOnAssertions = true;
     @NonNull
     private static LogProcessor logProcessor = new ConsoleLogProcessor(LcLevel.ERROR);
 
-    public static final int STACK_TRACE_CODE_DEPTH;
-
     static {
         final StackTraceElement[] stackTrace = Thread.currentThread().getStackTrace();
         int stackDepth;
@@ -164,7 +164,7 @@ public final class Lc {
      * @param message Message or format of message to log;
      * @param args    Arguments of formatted message.
      */
-    public static void e(@NonNull final String message, final Object... args) {
+    public static void e(@NonNull final String message, @NonNull final Object... args) {
         GENERAL_LC_GROUP.e(message, args);
     }
 
@@ -175,7 +175,7 @@ public final class Lc {
      * @param message   Message or format of message to log;
      * @param args      Arguments of formatted message.
      */
-    public static void e(@NonNull final Throwable throwable, @NonNull final String message, final Object... args) {
+    public static void e(@NonNull final Throwable throwable, @NonNull final String message, @NonNull final Object... args) {
         GENERAL_LC_GROUP.e(throwable, message, args);
     }
 
diff --git a/src/main/java/ru/touchin/roboswag/core/log/LcGroup.java b/src/main/java/ru/touchin/roboswag/core/log/LcGroup.java
index 4ced178..01777f9 100644
--- a/src/main/java/ru/touchin/roboswag/core/log/LcGroup.java
+++ b/src/main/java/ru/touchin/roboswag/core/log/LcGroup.java
@@ -186,7 +186,7 @@ public class LcGroup {
      * @param message Message or format of message to log;
      * @param args    Arguments of formatted message.
      */
-    public void e(@NonNull final String message, final Object... args) {
+    public void e(@NonNull final String message, @NonNull final Object... args) {
         logMessage(LcLevel.ERROR, message, null, args);
     }
 
@@ -197,7 +197,7 @@ public class LcGroup {
      * @param message   Message or format of message to log;
      * @param args      Arguments of formatted message.
      */
-    public void e(@NonNull final Throwable throwable, @NonNull final String message, final Object... args) {
+    public void e(@NonNull final Throwable throwable, @NonNull final String message, @NonNull final Object... args) {
         logMessage(LcLevel.ERROR, message, throwable, args);
     }
 
diff --git a/src/main/java/ru/touchin/roboswag/core/observables/Changeable.java b/src/main/java/ru/touchin/roboswag/core/observables/Changeable.java
index 40f4f1f..171fc42 100644
--- a/src/main/java/ru/touchin/roboswag/core/observables/Changeable.java
+++ b/src/main/java/ru/touchin/roboswag/core/observables/Changeable.java
@@ -27,6 +27,7 @@ import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
 import java.io.Serializable;
 
+import ru.touchin.roboswag.core.utils.ObjectUtils;
 import rx.Observable;
 import rx.subjects.BehaviorSubject;
 
@@ -50,7 +51,7 @@ public class Changeable<T> implements Serializable {
      *
      * @param value Value to set.
      */
-    public void set(final T value) {
+    public void set(@Nullable final T value) {
         subject.onNext(value);
     }
 
@@ -74,17 +75,17 @@ public class Changeable<T> implements Serializable {
         return subject.distinctUntilChanged();
     }
 
-    private void writeObject(final ObjectOutputStream outputStream) throws IOException {
+    private void writeObject(@NonNull final ObjectOutputStream outputStream) throws IOException {
         outputStream.writeObject(subject.getValue());
     }
 
     @SuppressWarnings("unchecked")
-    private void readObject(final ObjectInputStream inputStream) throws IOException, ClassNotFoundException {
+    private void readObject(@NonNull final ObjectInputStream inputStream) throws IOException, ClassNotFoundException {
         subject = BehaviorSubject.create((T) inputStream.readObject());
     }
 
     @Override
-    public boolean equals(final Object object) {
+    public boolean equals(@Nullable final Object object) {
         if (this == object) {
             return true;
         }
@@ -93,8 +94,7 @@ public class Changeable<T> implements Serializable {
         }
 
         final Changeable<?> that = (Changeable<?>) object;
-        return subject.getValue() != null ? subject.getValue().equals(that.subject.getValue()) : that.subject.getValue() == null;
-
+        return ObjectUtils.equals(subject.getValue(), that.subject.getValue());
     }
 
     @Override
diff --git a/src/main/java/ru/touchin/roboswag/core/observables/RxAndroidUtils.java b/src/main/java/ru/touchin/roboswag/core/observables/RxAndroidUtils.java
index 4e4c006..96ff8d6 100644
--- a/src/main/java/ru/touchin/roboswag/core/observables/RxAndroidUtils.java
+++ b/src/main/java/ru/touchin/roboswag/core/observables/RxAndroidUtils.java
@@ -98,7 +98,7 @@ public final class RxAndroidUtils {
 
         @SuppressWarnings("unchecked")
         @Override
-        public void onServiceConnected(final ComponentName name, final IBinder service) {
+        public void onServiceConnected(@NonNull final ComponentName name, @Nullable final IBinder service) {
             if (subscriber == null) {
                 return;
             }
@@ -111,7 +111,7 @@ public final class RxAndroidUtils {
         }
 
         @Override
-        public void onServiceDisconnected(final ComponentName name) {
+        public void onServiceDisconnected(@NonNull final ComponentName name) {
             if (subscriber != null) {
                 subscriber.onNext(null);
             }
@@ -121,8 +121,9 @@ public final class RxAndroidUtils {
 
     private static class LooperThread extends Thread {
 
+        @NonNull
         private final CountDownLatch isLooperInitialized = new CountDownLatch(1);
-        public Looper looper;
+        private Looper looper;
 
         @Override
         public void run() {
diff --git a/src/main/java/ru/touchin/roboswag/core/observables/collections/Change.java b/src/main/java/ru/touchin/roboswag/core/observables/collections/Change.java
index 168c80c..876d25f 100644
--- a/src/main/java/ru/touchin/roboswag/core/observables/collections/Change.java
+++ b/src/main/java/ru/touchin/roboswag/core/observables/collections/Change.java
@@ -103,6 +103,7 @@ public class Change<TItem> {
         return count;
     }
 
+    @NonNull
     @Override
     public String toString() {
         return type + " change of " + start + ":" + count;
diff --git a/src/main/java/ru/touchin/roboswag/core/observables/collections/loadable/MoreLoadRequest.java b/src/main/java/ru/touchin/roboswag/core/observables/collections/loadable/MoreLoadRequest.java
index 8e4830f..6cac3fc 100644
--- a/src/main/java/ru/touchin/roboswag/core/observables/collections/loadable/MoreLoadRequest.java
+++ b/src/main/java/ru/touchin/roboswag/core/observables/collections/loadable/MoreLoadRequest.java
@@ -60,10 +60,10 @@ public class MoreLoadRequest<TMoreReference> {
     }
 
     @Override
-    public boolean equals(final Object obj) {
-        return obj instanceof MoreLoadRequest
-                && ObjectUtils.equals(((MoreLoadRequest) obj).moreReference, moreReference)
-                && ((MoreLoadRequest) obj).nextPosition == nextPosition;
+    public boolean equals(@Nullable final Object object) {
+        return object instanceof MoreLoadRequest
+                && ObjectUtils.equals(((MoreLoadRequest) object).moreReference, moreReference)
+                && ((MoreLoadRequest) object).nextPosition == nextPosition;
     }
 
     @Override
diff --git a/src/main/java/ru/touchin/roboswag/core/observables/collections/loadable/NewerLoadRequest.java b/src/main/java/ru/touchin/roboswag/core/observables/collections/loadable/NewerLoadRequest.java
index d2d3619..6566bd9 100644
--- a/src/main/java/ru/touchin/roboswag/core/observables/collections/loadable/NewerLoadRequest.java
+++ b/src/main/java/ru/touchin/roboswag/core/observables/collections/loadable/NewerLoadRequest.java
@@ -60,10 +60,10 @@ public class NewerLoadRequest<TNewerReference> {
     }
 
     @Override
-    public boolean equals(final Object obj) {
-        return obj instanceof NewerLoadRequest
-                && ObjectUtils.equals(((NewerLoadRequest) obj).newerReference, newerReference)
-                && ((NewerLoadRequest) obj).newerItemsCount == newerItemsCount;
+    public boolean equals(@Nullable final Object object) {
+        return object instanceof NewerLoadRequest
+                && ObjectUtils.equals(((NewerLoadRequest) object).newerReference, newerReference)
+                && ((NewerLoadRequest) object).newerItemsCount == newerItemsCount;
     }
 
     @Override
diff --git a/src/main/java/ru/touchin/roboswag/core/utils/ObjectUtils.java b/src/main/java/ru/touchin/roboswag/core/utils/ObjectUtils.java
index 7f9c1da..a6170dc 100644
--- a/src/main/java/ru/touchin/roboswag/core/utils/ObjectUtils.java
+++ b/src/main/java/ru/touchin/roboswag/core/utils/ObjectUtils.java
@@ -107,7 +107,7 @@ public final class ObjectUtils {
     }
 
     @SuppressWarnings("PMD.AvoidUsingShortType")
-    private static boolean isArraysEquals(@NonNull final Object object1, @Nullable final Object object2, final Class<?> elementType) {
+    private static boolean isArraysEquals(@NonNull final Object object1, @Nullable final Object object2, @NonNull final Class<?> elementType) {
         if (object1 instanceof Object[]) {
             return Arrays.deepEquals((Object[]) object1, (Object[]) object2);
         } else if (elementType == int.class) {
diff --git a/src/main/java/ru/touchin/roboswag/core/utils/ThreadLocalValue.java b/src/main/java/ru/touchin/roboswag/core/utils/ThreadLocalValue.java
index ce8b235..6efbcc7 100644
--- a/src/main/java/ru/touchin/roboswag/core/utils/ThreadLocalValue.java
+++ b/src/main/java/ru/touchin/roboswag/core/utils/ThreadLocalValue.java
@@ -32,14 +32,23 @@ public class ThreadLocalValue<T> extends ThreadLocal<T> {
     @NonNull
     private final Func0<T> creator;
 
-    public ThreadLocalValue(@NonNull final Func0<T> creator) {
+    public ThreadLocalValue(@NonNull final NonNullFunc<T> creator) {
         super();
         this.creator = creator;
     }
 
+    @NonNull
     @Override
     protected T initialValue() {
         return creator.call();
     }
 
+    public interface NonNullFunc<T> extends Func0<T> {
+
+        @NonNull
+        @Override
+        T call();
+
+    }
+
 }
\ No newline at end of file
diff --git a/src/main/java/ru/touchin/roboswag/core/utils/pairs/HalfNullablePair.java b/src/main/java/ru/touchin/roboswag/core/utils/pairs/HalfNullablePair.java
index e00d0b4..fbee09d 100644
--- a/src/main/java/ru/touchin/roboswag/core/utils/pairs/HalfNullablePair.java
+++ b/src/main/java/ru/touchin/roboswag/core/utils/pairs/HalfNullablePair.java
@@ -66,7 +66,7 @@ public class HalfNullablePair<TFirst, TSecond> implements Serializable {
     }
 
     @Override
-    public boolean equals(final Object object) {
+    public boolean equals(@Nullable final Object object) {
         if (this == object) {
             return true;
         }
diff --git a/src/main/java/ru/touchin/roboswag/core/utils/pairs/NonNullPair.java b/src/main/java/ru/touchin/roboswag/core/utils/pairs/NonNullPair.java
index ae6592a..f185c66 100644
--- a/src/main/java/ru/touchin/roboswag/core/utils/pairs/NonNullPair.java
+++ b/src/main/java/ru/touchin/roboswag/core/utils/pairs/NonNullPair.java
@@ -20,6 +20,7 @@
 package ru.touchin.roboswag.core.utils.pairs;
 
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 
 import java.io.Serializable;
 
@@ -65,7 +66,7 @@ public class NonNullPair<TFirst, TSecond> implements Serializable {
     }
 
     @Override
-    public boolean equals(final Object object) {
+    public boolean equals(@Nullable final Object object) {
         if (this == object) {
             return true;
         }
diff --git a/src/main/java/ru/touchin/roboswag/core/utils/pairs/NullablePair.java b/src/main/java/ru/touchin/roboswag/core/utils/pairs/NullablePair.java
index 28c4b4b..21f630d 100644
--- a/src/main/java/ru/touchin/roboswag/core/utils/pairs/NullablePair.java
+++ b/src/main/java/ru/touchin/roboswag/core/utils/pairs/NullablePair.java
@@ -70,17 +70,17 @@ public class NullablePair<TFirst, TSecond> implements Serializable { //todo: mb
     }
 
     @Override
-    public boolean equals(final Object obj) {
-        if (this == obj) {
+    public boolean equals(@Nullable final Object object) {
+        if (this == object) {
             return true;
         }
-        if (obj == null || getClass() != obj.getClass()) {
+        if (object == null || getClass() != object.getClass()) {
             return false;
         }
 
-        final NullablePair<?, ?> that = (NullablePair<?, ?>) obj;
+        final NullablePair<?, ?> that = (NullablePair<?, ?>) object;
 
-        return ObjectUtils.equals(first, that.getFirst()) && ObjectUtils.equals(second, that.getSecond());
+        return ObjectUtils.equals(first, that.first) && ObjectUtils.equals(second, that.second);
     }
 
     @Override