Update charted to 0.4.8 and roll

packages/quiver/lib/src/cache/cache.dart

 // Copyright 2013 Google Inc. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
 part of quiver.cache;
 
-/**
- * A function that produces a value for [key], for when a [Cache] needs to
- * populate an entry.
- *
- * The loader function should either return a value synchronously or a [Future]
- * which completes with the value asynchronously.
- */
+/// A function that produces a value for [key], for when a [Cache] needs to
+/// populate an entry.
+///
+/// The loader function should either return a value synchronously or a
+/// [Future] which completes with the value asynchronously.
 typedef dynamic Loader<K>(K key);
 
-/**
- * A semi-persistent mapping of keys to values.
- *
- * All access to a Cache is asynchronous because many implementations will store
- * their entries in remote systems, isolates, or otherwise have to do async IO
- * to read and write.
- */
+/// A semi-persistent mapping of keys to values.
+///
+/// All access to a Cache is asynchronous because many implementations will
+/// store their entries in remote systems, isolates, or otherwise have to do
+/// async IO to read and write.
 abstract class Cache<K, V> {
-
-  /**
-   * Returns the value associated with [key].
-   */
+  /// Returns the value associated with [key].
   Future<V> get(K key, {Loader<K> ifAbsent});
 
-  /**
-   * Sets the value associated with [key]. The Future completes with null when
-   * the operation is complete.
-   */
+  /// Sets the value associated with [key]. The Future completes with null when
+  /// the operation is complete.
   Future set(K key, V value);
 
-  /**
-   * Removes the value associated with [key]. The Future completes with null
-   * when the operation is complete.
-   */
+  /// Removes the value associated with [key]. The Future completes with null
+  /// when the operation is complete.
   Future invalidate(K key);
 }