Adding support for docgen:value:EmptyValue

This helps in creating empty json docs

Author: ashwin2002

src/main/java/utils/docgen/DocumentGenerator.java

@@ -17,6 +17,7 @@
 import utils.key.ReverseKey;
 import utils.key.SimpleKey;
 import utils.val.Cars;
+import utils.val.EmptyValue;
 import utils.val.Hotel;
 import utils.val.HeterogeneousHotel;
 import utils.val.MiniCars;
@@ -164,6 +165,8 @@ else if (valClass.equals(SimpleSubDocValue.class.getSimpleName()))
             this.valInstance = SimpleSubDocValue.class;
         else if (valClass.equals(RandomlyNestedJson.class.getSimpleName()))
             this.valInstance = RandomlyNestedJson.class;
+        else if (valClass.equals(EmptyValue.class.getSimpleName()))
+            this.valInstance = EmptyValue.class;
         else
             this.valInstance = SimpleValue.class;
     }

src/main/java/utils/val/EmptyValue.java

@@ -0,0 +1,18 @@
+package utils.val;
+
+import utils.docgen.WorkLoadSettings;
+
+import java.util.Collections;
+import java.util.Map;
+
+public class EmptyValue {
+    public WorkLoadSettings ws;
+
+    public EmptyValue(WorkLoadSettings ws) {
+        this.ws = ws;
+    }
+
+    public Map<String, Object> next(String key) {
+        return Collections.emptyMap();
+    }
+}