Update to Drupal 8.2.0. For more information, see https://www.drupal.org/project/drupal/releases/8.2.0

core/lib/Drupal/Core/Logger/LoggerChannelTrait.php

@@ -0,0 +1,58 @@
+<?php
+
+namespace Drupal\Core\Logger;
+
+/**
+ * Wrapper methods for the logger factory service.
+ *
+ * This utility trait should only be used in application-level code, such as
+ * classes that would implement ContainerInjectionInterface. Services registered
+ * in the Container should not use this trait but inject the appropriate service
+ * directly for easier testing.
+ *
+ * @see \Drupal\Core\DependencyInjection\ContainerInjectionInterface
+ */
+trait LoggerChannelTrait {
+
+  /**
+   * The logger channel factory service.
+   *
+   * @var \Drupal\Core\Logger\LoggerChannelFactoryInterface
+   */
+  protected $loggerFactory;
+
+  /**
+   * Gets the logger for a specific channel.
+   *
+   * @param string $channel
+   *   The name of the channel. Can be any string, but the general practice is
+   *   to use the name of the subsystem calling this.
+   *
+   * @return \Psr\Log\LoggerInterface
+   *   The logger for the given channel.
+   *
+   * @todo Require the use of injected services:
+   *   https://www.drupal.org/node/2733703
+   */
+  protected function getLogger($channel) {
+    if (!$this->loggerFactory) {
+      $this->loggerFactory = \Drupal::service('logger.factory');
+    }
+    return $this->loggerFactory->get($channel);
+  }
+
+  /**
+   * Injects the logger channel factory.
+   *
+   * @param \Drupal\Core\Logger\LoggerChannelFactoryInterface $logger_factory
+   *   The logger channel factory service.
+   *
+   * @return $this
+   */
+  public function setLoggerFactory(LoggerChannelFactoryInterface $logger_factory) {
+    $this->loggerFactory = $logger_factory;
+
+    return $this;
+  }
+
+}