HCOLL-136 HCOLL-137 HCOLL-164 Extracted ChronicleHash abstraction and updated ChronicleMap docs

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

@@ -17,8 +17,8 @@
 package net.openhft.chronicle.set;
 
 import net.openhft.chronicle.map.ChronicleMap;
-import net.openhft.chronicle.map.ChronicleSet;
 
+import java.io.File;
 import java.io.IOException;
 import java.io.Serializable;
 import java.util.AbstractSet;
@@ -115,6 +115,11 @@ class SetFromMap<E> extends AbstractSet<E>
         return m.longSize();
     }
 
+    @Override
+    public File file() {
+        return m.file();
+    }
+
     @Override
     public void close() throws IOException {
         m.close();