move transit to place

core/src/main/java/ru/trader/core/Place.java

@@ -70,4 +70,8 @@ public interface Place extends Connectable<Place> {
             vendor.clear();
         }
     }
+
+    default Vendor asTransit(){
+        return new TransitVendor(this);
+    }
 }

core/src/main/java/ru/trader/core/VendorsIterator.java

@@ -31,7 +31,7 @@ public class VendorsIterator implements Iterator<Vendor> {
                 nextVendor();
             } else {
                 if (includeTransit)
-                    next = new TransitVendor(place);
+                    next = place.asTransit();
                 else
                     nextPlace();
             }