Merge pull request #148 from JetBrains/fix/XD-984-adhere-iterator-con…

…tract

fix/XD-984-adhere-iterator-contract

entity-store/src/main/kotlin/jetbrains/exodus/entitystore/orientdb/iterate/OQueryEntityIterator.kt

@@ -42,7 +42,7 @@ class OQueryEntityIterator(private val source: Iterator<Entity>) : EntityIterato
         }
     }
 
-    override fun next(): Entity? {
+    override fun next(): Entity {
         return source.next()
     }
 
@@ -61,7 +61,7 @@ class OQueryEntityIterator(private val source: Iterator<Entity>) : EntityIterato
     }
 
     override fun nextId(): EntityId? {
-        return next()?.id
+        return next().id
     }
 
     override fun dispose(): Boolean {