diff --git a/framework/caching/Cache.php b/framework/caching/Cache.php
index ce25a5b..20631a7 100644
--- a/framework/caching/Cache.php
+++ b/framework/caching/Cache.php
@@ -77,10 +77,12 @@ abstract class Cache extends ApplicationComponent implements \ArrayAccess
 	 * For example:
 	 *
 	 * ~~~
-	 * $key = Cache::buildKey($className, $method, $id);
+	 * $key = $cache->buildKey($className, $method, $id);
 	 * ~~~
 	 *
+	 * @param string $id the
 	 * @return string the cache key
+	 * @throws InvalidCallException if the method receives no parameter
 	 */
 	public function generateKey($id)
 	{
diff --git a/framework/caching/Dependency.php b/framework/caching/Dependency.php
index 22d1d3f..2e66145 100644
--- a/framework/caching/Dependency.php
+++ b/framework/caching/Dependency.php
@@ -42,7 +42,7 @@ abstract class Dependency extends \yii\base\Object
 	 */
 	public function getHasChanged()
 	{
-		return $this->generateDependencyData() != $this->data;
+		return $this->generateDependencyData() !== $this->data;
 	}
 
 	/**
diff --git a/framework/logging/Logger.php b/framework/logging/Logger.php
index 43ea916..de69f93 100644
--- a/framework/logging/Logger.php
+++ b/framework/logging/Logger.php
@@ -12,8 +12,8 @@ namespace yii\logging;
 /**
  * Logger records logged messages in memory.
  *
- * When [[flushInterval]] is reached or when application terminates, it will
- * call [[flush]] to send logged messages to different log targets, such as
+ * When [[flushInterval()]] is reached or when application terminates, it will
+ * call [[flush()]] to send logged messages to different log targets, such as
  * file, email, Web.
  *
  * Logger provides a set of events for further customization: