diff --git a/src/main/java/net/openhft/chronicle/map/StatelessChronicleMap.java b/src/main/java/net/openhft/chronicle/map/StatelessChronicleMap.java
index 18074c7cb..9935f713f 100644
--- a/src/main/java/net/openhft/chronicle/map/StatelessChronicleMap.java
+++ b/src/main/java/net/openhft/chronicle/map/StatelessChronicleMap.java
@@ -27,6 +27,7 @@ import net.openhft.lang.io.NativeBytes;
 import net.openhft.lang.thread.NamedThreadFactory;
 import net.openhft.lang.threadlocal.ThreadLocalCopies;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -60,6 +61,7 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
     private final byte[] connectionByte = new byte[1];
     private final ByteBuffer connectionOutBuffer = ByteBuffer.wrap(connectionByte);
     private final String name;
+    @NotNull
     private final AbstractChronicleMapBuilder chronicleMapBuilder;
 
     private volatile ByteBuffer outBuffer;
@@ -68,13 +70,19 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
     private volatile ByteBuffer inBuffer;
     private volatile ByteBufferBytes inBytes;
 
+    @NotNull
     private final ReaderWithSize<K> keyReaderWithSize;
+    @NotNull
     private final WriterWithSize<K> keyWriterWithSize;
+    @NotNull
     private final ReaderWithSize<V> valueReaderWithSize;
+    @NotNull
     private final WriterWithSize<V> valueWriterWithSize;
     private volatile SocketChannel clientChannel;
 
+    @Nullable
     private CloseablesManager closeables;
+    @NotNull
     private final StatelessMapConfig config;
     private int maxEntrySize;
     private final Class<K> kClass;
@@ -117,10 +125,11 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
         UPDATE_FOR_KEY
     }
 
+    @NotNull
     private AtomicLong transactionID = new AtomicLong(0);
 
-    StatelessChronicleMap(final StatelessMapConfig config,
-                          final AbstractChronicleMapBuilder chronicleMapBuilder) throws IOException {
+    StatelessChronicleMap(@NotNull final StatelessMapConfig config,
+                          @NotNull final AbstractChronicleMapBuilder chronicleMapBuilder) throws IOException {
         this.chronicleMapBuilder = chronicleMapBuilder;
         this.config = config;
         keyReaderWithSize = new ReaderWithSize<>(chronicleMapBuilder.keyBuilder);
@@ -148,9 +157,11 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
 
     }
 
+    @NotNull
     @Override
     public Future<V> getLater(@NotNull final K key) {
         return lazyExecutorService().submit(new Callable<V>() {
+            @Nullable
             @Override
             public V call() throws Exception {
                 return StatelessChronicleMap.this.get(key);
@@ -158,9 +169,11 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
         });
     }
 
+    @NotNull
     @Override
     public Future<V> putLater(@NotNull final K key, @NotNull final V value) {
         return lazyExecutorService().submit(new Callable<V>() {
+            @Nullable
             @Override
             public V call() throws Exception {
                 return StatelessChronicleMap.this.put(key, value);
@@ -312,6 +325,7 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
             LOG.debug("Attached to a map with a remote identifier=" + remoteIdentifier);
     }
 
+    @NotNull
     public File file() {
         throw new UnsupportedOperationException();
     }
@@ -400,7 +414,7 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
      * @return true if the contain the same data
      */
     @Override
-    public boolean equals(Object object) {
+    public boolean equals(@Nullable Object object) {
         if (this == object) return true;
         if (object == null || object.getClass().isAssignableFrom(Map.class))
             return false;
@@ -421,6 +435,7 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
         return fetchInt(HASH_CODE);
     }
 
+    @NotNull
     public String toString() {
         return fetchObject(String.class, TO_STRING);
     }
@@ -434,6 +449,7 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
         return fetchBooleanK(CONTAINS_KEY, (K) key);
     }
 
+    @NotNull
     private NullPointerException keyNotNullNPE() {
         return new NullPointerException("key can not be null");
     }
@@ -450,11 +466,13 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
         return fetchObject(vClass, GET, (K) key);
     }
 
+    @NotNull
     public V getUsing(K key, V usingValue) {
         throw new UnsupportedOperationException("getUsing() is not supported for stateless " +
                 "clients");
     }
 
+    @NotNull
     public V acquireUsing(@NotNull K key, V usingValue) {
         throw new UnsupportedOperationException("acquireUsing() is not supported for stateless " +
                 "clients");
@@ -485,22 +503,24 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
         return fetchObject(vClass, putReturnsNull ? PUT_WITHOUT_ACC : PUT, key, value);
     }
 
-    public <R> R mapForKey(K key, @NotNull Function<? super V, R> function) {
+    @Nullable
+    public <R> R mapForKey(@Nullable K key, @NotNull Function<? super V, R> function) {
         if (key == null)
             throw keyNotNullNPE();
         return fetchObject(MAP_FOR_KEY, key, function);
     }
 
 
+    @Nullable
     @Override
-    public <R> R updateForKey(K key, @NotNull Mutator<? super V, R> mutator) {
+    public <R> R updateForKey(@Nullable K key, @NotNull Mutator<? super V, R> mutator) {
         if (key == null)
             throw keyNotNullNPE();
         return fetchObject(UPDATE_FOR_KEY, key, mutator);
     }
 
 
-    private synchronized void writeEntriesForPutAll(Map<? extends K, ? extends V> map) {
+    private synchronized void writeEntriesForPutAll(@NotNull Map<? extends K, ? extends V> map) {
         final int numberOfEntries = map.size();
         int numberOfEntriesReadSoFar = 0;
 
@@ -850,7 +870,7 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
     }
 
 
-    private long writeEvent(StatelessChronicleMap.EventId event) {
+    private long writeEvent(@NotNull StatelessChronicleMap.EventId event) {
         outBuffer.clear();
         outBytes.clear();
 
@@ -862,7 +882,7 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
     /**
      * skips for the transactionid
      */
-    private long writeEventAnSkip(EventId event) {
+    private long writeEventAnSkip(@NotNull EventId event) {
         final long sizeLocation = writeEvent(event);
 
         // skips for the transaction id
@@ -917,6 +937,7 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
                     (value == null ? 0 : value.hashCode());
         }
 
+        @NotNull
         public final String toString() {
             return getKey() + "=" + getValue();
         }
@@ -952,7 +973,7 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
                     outBytes.buffer().clear();
                     break;
 
-                } catch (java.nio.channels.ClosedChannelException | ClosedConnectionException e) {
+                } catch (@NotNull java.nio.channels.ClosedChannelException | ClosedConnectionException e) {
                     checkTimeout(timeoutTime);
                     clientChannel = lazyConnect(config.timeoutMs(), config.remoteAddress());
                 }
@@ -1148,7 +1169,7 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
     }
 
 
-    private void send(final Bytes out, long timeoutTime) throws IOException {
+    private void send(@NotNull final Bytes out, long timeoutTime) throws IOException {
 
         outBuffer.limit((int) out.position());
         outBuffer.position(0);
@@ -1270,7 +1291,7 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
         }
     }
 
-    private void resizeToMessage(long start, IllegalArgumentException e) {
+    private void resizeToMessage(long start, @NotNull IllegalArgumentException e) {
         String message = e.getMessage();
         if (message.startsWith(START_OF)) {
             String substring = message.substring("Attempt to write ".length(), message.length());
@@ -1298,6 +1319,7 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
         }
     }
 
+    @Nullable
     private <O> O readObject(long transactionId, long startTime) {
         long timeoutTime = startTime + this.config.timeoutMs();
 
@@ -1335,7 +1357,7 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
         }
     }
 
-    private long send(final EventId eventId, final long startTime) {
+    private long send(@NotNull final EventId eventId, final long startTime) {
         // send
         outBytesLock.lock();
         try {
@@ -1350,7 +1372,7 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
         return valueReaderWithSize.readNullable(in, copies);
     }
 
-    private boolean fetchBoolean(final EventId eventId, K key, V value) {
+    private boolean fetchBoolean(@NotNull final EventId eventId, K key, V value) {
         final long startTime = System.currentTimeMillis();
         ThreadLocalCopies copies;
 
@@ -1373,7 +1395,7 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
 
     }
 
-    private boolean fetchBoolean(final EventId eventId, K key, V value1, V value2) {
+    private boolean fetchBoolean(@NotNull final EventId eventId, K key, V value1, V value2) {
         final long startTime = System.currentTimeMillis();
         ThreadLocalCopies copies;
 
@@ -1397,7 +1419,7 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
 
     }
 
-    private boolean fetchBooleanV(final EventId eventId, V value) {
+    private boolean fetchBooleanV(@NotNull final EventId eventId, V value) {
         final long startTime = System.currentTimeMillis();
 
         long transactionId;
@@ -1415,7 +1437,7 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
     }
 
 
-    private boolean fetchBooleanK(final EventId eventId, K key) {
+    private boolean fetchBooleanK(@NotNull final EventId eventId, K key) {
         final long startTime = System.currentTimeMillis();
 
         long transactionId;
@@ -1433,7 +1455,7 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
     }
 
 
-    private long fetchLong(final EventId eventId) {
+    private long fetchLong(@NotNull final EventId eventId) {
         final long startTime = System.currentTimeMillis();
 
         long transactionId;
@@ -1449,7 +1471,7 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
         return readLong(transactionId, startTime);
     }
 
-    private boolean fetchBoolean(final EventId eventId) {
+    private boolean fetchBoolean(@NotNull final EventId eventId) {
         final long startTime = System.currentTimeMillis();
 
         long transactionId;
@@ -1465,7 +1487,7 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
         return readBoolean(transactionId, startTime);
     }
 
-    private void fetchVoid(final EventId eventId) {
+    private void fetchVoid(@NotNull final EventId eventId) {
 
         final long startTime = System.currentTimeMillis();
 
@@ -1495,7 +1517,8 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
     }
 
 
-    private <O> O fetchObject(final Class<O> tClass, final EventId eventId) {
+    @Nullable
+    private <O> O fetchObject(final Class<O> tClass, @NotNull final EventId eventId) {
         final long startTime = System.currentTimeMillis();
         long transactionId = send(eventId, startTime);
 
@@ -1511,7 +1534,7 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
     }
 
 
-    private int fetchInt(final EventId eventId) {
+    private int fetchInt(@NotNull final EventId eventId) {
         final long startTime = System.currentTimeMillis();
 
         long transactionId;
@@ -1528,7 +1551,8 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
     }
 
 
-    private <R> R fetchObject(Class<R> rClass, final EventId eventId, K key, V value) {
+    @Nullable
+    private <R> R fetchObject(Class<R> rClass, @NotNull final EventId eventId, K key, V value) {
         final long startTime = System.currentTimeMillis();
         ThreadLocalCopies copies;
 
@@ -1559,7 +1583,8 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
                     "supported");
     }
 
-    private <R> R fetchObject(Class<R> rClass, final EventId eventId, K key, V value1, V value2) {
+    @Nullable
+    private <R> R fetchObject(Class<R> rClass, @NotNull final EventId eventId, K key, V value1, V value2) {
         final long startTime = System.currentTimeMillis();
         ThreadLocalCopies copies;
 
@@ -1592,7 +1617,8 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
                     "supported");
     }
 
-    private <R> R fetchObject(Class<R> rClass, final EventId eventId, K key) {
+    @Nullable
+    private <R> R fetchObject(Class<R> rClass, @NotNull final EventId eventId, K key) {
         final long startTime = System.currentTimeMillis();
         ThreadLocalCopies copies;
 
@@ -1622,7 +1648,7 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
     }
 
 
-    private boolean eventReturnsNull(EventId eventId) {
+    private boolean eventReturnsNull(@NotNull EventId eventId) {
 
         switch (eventId) {
             case PUT_ALL_WITHOUT_ACC:
@@ -1654,7 +1680,8 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable, Clon
     }
 
 
-    private <R> R fetchObject(final EventId eventId, K key, Object object) {
+    @Nullable
+    private <R> R fetchObject(@NotNull final EventId eventId, K key, @NotNull Object object) {
         final long startTime = System.currentTimeMillis();
         long transactionId;