provide a way to enumerate entities managed by the DataStack

CoreStore/Internal/NSManagedObjectModel+Setup.swift

@@ -150,6 +150,15 @@ internal extension NSManagedObjectModel {
         return self.entityNameMapping[NSStringFromClass(entityClass)]!
     }
     
+    @nonobjc internal func entityMapping() -> [String: NSManagedObject.Type] {
+    
+        return self.entityNameMapping.reduce([:]) { (var mapping, pair) in
+            
+            mapping[pair.0] = (NSClassFromString(pair.1)! as! NSManagedObject.Type)
+            return mapping
+        }
+    }
+    
     @nonobjc internal func mergedModels() -> [NSManagedObjectModel] {
         
         return self.modelVersions?.map { self[$0] }.flatMap { $0 == nil ? [] : [$0!] } ?? [self]

CoreStore/Setting Up/DataStack.swift

@@ -81,6 +81,14 @@ public final class DataStack {
         return self.model.currentModelVersion!
     }
     
+    /**
+    Returns the entity name-to-class type mapping from the `DataStack`'s model.
+    */
+    public var entitiesByName: [String: NSManagedObject.Type] {
+        
+        return self.model.entityMapping()
+    }
+    
     /**
     Adds an in-memory store to the stack.