Add 'Drafted' interface and extend the InsertOperation to recognize that so as to be able to persist the mutated set of keys only yet return a pojo with values matching the draft, not just the mutations.

pom.xml

@@ -5,7 +5,7 @@
     <modelVersion>4.0.0</modelVersion>
     <groupId>net.helenus</groupId>
     <artifactId>helenus-core</artifactId>
-    <version>2.0.14-SNAPSHOT</version>
+    <version>2.0.15-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>helenus</name>

src/main/java/net/helenus/core/HelenusSession.java

@@ -19,6 +19,7 @@ import java.io.Closeable;
 import java.io.PrintStream;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Set;
 import java.util.concurrent.Executor;
 import java.util.concurrent.TimeUnit;
 import java.util.function.Function;
@@ -31,6 +32,7 @@ import com.google.common.cache.CacheBuilder;
 import com.diffplug.common.base.Errors;
 
 import net.helenus.core.operation.*;
+import net.helenus.core.reflect.Drafted;
 import net.helenus.core.reflect.HelenusPropertyNode;
 import net.helenus.mapping.HelenusEntity;
 import net.helenus.mapping.MappingUtil;
@@ -346,13 +348,21 @@ public final class HelenusSession extends AbstractSessionOperations implements C
 		return new InsertOperation(this, true);
 	}
 
-	public InsertOperation insert(Object pojo) {
+    public InsertOperation insert(Object pojo) {
+        return insert(pojo, null);
+    }
+
+    public InsertOperation insert(Drafted draft) {
+	    return insert(draft.build(), draft.mutated());
+    }
+
+    public InsertOperation insert(Object pojo, Set<String> mutations) {
 		Objects.requireNonNull(pojo, "pojo is empty");
 
 		Class<?> iface = MappingUtil.getMappingInterface(pojo);
 		HelenusEntity entity = Helenus.entity(iface);
 
-		return new InsertOperation(this, entity, pojo, true);
+		return new InsertOperation(this, entity, pojo, mutations, true);
 	}
 
 	public InsertOperation upsert() {
@@ -365,7 +375,7 @@ public final class HelenusSession extends AbstractSessionOperations implements C
 		Class<?> iface = MappingUtil.getMappingInterface(pojo);
 		HelenusEntity entity = Helenus.entity(iface);
 
-		return new InsertOperation(this, entity, pojo, false);
+		return new InsertOperation(this, entity, pojo, null, false);
 	}
 
 	public DeleteOperation delete() {

src/main/java/net/helenus/core/operation/InsertOperation.java

@@ -48,21 +48,14 @@ public final class InsertOperation extends AbstractOperation<ResultSet, InsertOp
         this.ifNotExists = ifNotExists;
     }
 
-    public InsertOperation(AbstractSessionOperations sessionOperations, HelenusEntity entity, Object pojo,
-            boolean ifNotExists) {
+    public InsertOperation(AbstractSessionOperations sessionOperations, HelenusEntity entity,
+            Object pojo, Set<String> mutations, boolean ifNotExists) {
         super(sessionOperations);
 
         this.entity = entity;
         this.ifNotExists = ifNotExists;
         Collection<HelenusProperty> properties = entity.getOrderedProperties();
-        Set<String> keys = null;
-
-        if (pojo instanceof MapExportable) {
-            keys = ((MapExportable) pojo).mutated();
-            if (keys == null) {
-                keys = ((MapExportable) pojo).toMap().keySet();
-            }
-        }
+        Set<String> keys = (mutations == null) ?  ((MapExportable) pojo).toMap().keySet() : mutations;
 
         for (HelenusProperty prop : properties) {
 

src/main/java/net/helenus/core/reflect/Drafted.java

@@ -0,0 +1,11 @@
+package net.helenus.core.reflect;
+
+import java.util.Set;
+
+public interface Drafted<T> extends MapExportable {
+
+    Set<String> mutated();
+
+    T build();
+
+}

src/main/java/net/helenus/core/reflect/MapExportable.java

@@ -16,7 +16,6 @@
 package net.helenus.core.reflect;
 
 import java.util.Map;
-import java.util.Set;
 
 public interface MapExportable {
 
@@ -24,6 +23,4 @@ public interface MapExportable {
 
 	Map<String, Object> toMap();
 
-	default Set<String> mutated() { return null; }
-
 }

src/test/java/net/helenus/test/unit/core/dsl/Account.java

@@ -16,7 +16,10 @@
 package net.helenus.test.unit.core.dsl;
 
 import java.util.Date;
+import java.util.Map;
+import java.util.Set;
 
+import net.helenus.core.reflect.Drafted;
 import net.helenus.mapping.annotation.*;
 
 @Table
@@ -35,6 +38,21 @@ public interface Account {
 
 	@Transient
 	default Draft draft() { return new Draft(); }
-	class Draft {}
+	class Draft implements Drafted { //TODO
+		@Override
+		public Set<String> mutated() {
+			return null;
+		}
+
+		@Override
+		public Object build() {
+			return null;
+		}
+
+		@Override
+		public Map<String, Object> toMap() {
+			return null;
+		}
+	}
 
 }