Add docs

lib/src/box/lazy_box.dart

@@ -3,7 +3,13 @@ part of hive;
 /// [LazyBox]es don't keep the values in memory like normal boxes. Each time a
 /// value is read, it is loaded from the backend.
 abstract class LazyBox<E> extends BoxBase<E> {
+  /// Returns the value associated with the given [key]. If the key does not
+  /// exist, `null` is returned.
+  ///
+  /// If [defaultValue] is specified, it is returned in case the key does not
+  /// exist.
   Future<E> get(dynamic key, {E defaultValue});
 
+  /// Returns the value associated with the n-th key.
   Future<E> getAt(int index);
 }

lib/src/object/hive_collection.dart

@@ -1,17 +1,24 @@
 part of hive;
 
 abstract class HiveCollection<E extends HiveObject> implements List<E> {
+  /// The box which contains all the objects in this collection
   BoxBase get box;
 
+  /// The keys of all the objects in this collection.
   Iterable<dynamic> get keys;
 
+  /// Delete all objects in this collection from Hive.
   Future<void> deleteAllFromHive();
 
+  /// Delete the first object in this collection from Hive.
   Future<void> deleteFirstFromHive();
 
+  /// Delete the last object in this collection from Hive.
   Future<void> deleteLastFromHive();
 
+  /// Delete the object at [index] from Hive.
   Future<void> deleteFromHive(int index);
 
+  /// Converts this collection to a Map.
   Map<dynamic, E> toMap();
 }

lib/src/object/hive_list.dart

@@ -3,10 +3,14 @@ part of hive;
 @experimental
 abstract class HiveList<E extends HiveObject> extends HiveCollection<E>
     implements List<E> {
+  /// Create a new HiveList which can contain HiveObjects from [box].
   factory HiveList(Box box, {List<E> objects}) =>
       HiveListImpl(box, objects: objects);
 
+  /// Disposes this list. It is important to call this method when the list is
+  /// no longer used to avoid memory leaks.
   void dispose();
 
+  /// Casts the list to a new HiveList.
   HiveList<T> castHiveList<T extends HiveObject>();
 }

lib/src/object/hive_list_impl.dart

@@ -114,7 +114,7 @@ class HiveListImpl<E extends HiveObject>
     if (obj == null) {
       throw HiveError('HiveLists must not contain null elements.');
     } else if (obj.box != box) {
-      throw HiveError('The HiveObject needs to be in the box "$boxName".');
+      throw HiveError('HiveObjects needs to be in the box "$boxName".');
     }
   }