create() and close() to not throw an IOException.

src/main/java/net/openhft/chronicle/hash/ChronicleHash.java

@@ -23,7 +23,6 @@ import net.openhft.chronicle.set.ChronicleSet;
 
 import java.io.Closeable;
 import java.io.File;
-import java.io.IOException;
 
 /**
  * This interface defines common {@link ChronicleMap} and {@link ChronicleSet}, related to off-heap
@@ -61,5 +60,5 @@ public interface ChronicleHash extends Closeable {
      * <i>any</i> exception, or even JVM crash. Shortly speaking, don't call use map closing.
      */
     @Override
-    void close() throws IOException;
+    void close();
 }

src/main/java/net/openhft/chronicle/map/AbstractChronicleMapBuilder.java

@@ -782,7 +782,7 @@ public abstract class AbstractChronicleMapBuilder<K, V,
     }
 
     @Override
-    public ChronicleMap<K, V> create() throws IOException {
+    public ChronicleMap<K, V> create() {
         // clone() to make this builder instance thread-safe, because createWithoutFile() method
         // computes some state based on configurations, but doesn't synchronize on configuration
         // changes.
@@ -856,12 +856,17 @@ public abstract class AbstractChronicleMapBuilder<K, V,
     }
 
     ChronicleMap<K, V> createWithoutFile(
-            SingleChronicleHashReplication singleHashReplication, ReplicationChannel channel) throws IOException {
-        VanillaChronicleMap<K, ?, ?, V, ?, ?> map = newMap(singleHashReplication, channel);
-        BytesStore bytesStore = new DirectStore(JDKObjectSerializer.INSTANCE,
-                map.sizeInBytes(), true);
-        map.createMappedStoreAndSegments(bytesStore);
-        return establishReplication(map, singleHashReplication, channel);
+            SingleChronicleHashReplication singleHashReplication, ReplicationChannel channel) {
+        try {
+            VanillaChronicleMap<K, ?, ?, V, ?, ?> map = newMap(singleHashReplication, channel);
+            BytesStore bytesStore = new DirectStore(JDKObjectSerializer.INSTANCE,
+                    map.sizeInBytes(), true);
+            map.createMappedStoreAndSegments(bytesStore);
+            return establishReplication(map, singleHashReplication, channel);
+        } catch (IOException e) {
+            // file-less version should never trigger an IOException.
+            throw new AssertionError(e);
+        }
     }
 
     ChronicleMap<K, V> createStatelessMap(StatelessMapConfig<K, V> statelessBuilder)

src/main/java/net/openhft/chronicle/set/SetFromMap.java

@@ -123,7 +123,7 @@ class SetFromMap<E> extends AbstractSet<E>
     }
 
     @Override
-    public void close() throws IOException {
+    public void close() {
         m.close();
     }
 }