commit f5d12834afe6ab1a33f836b2c69c3a982519635b
Author: kpv <kpv@758986.no-reply.drupal.org>
Date:   Wed Dec 2 10:04:55 2015 -0500

    Issue #2366069 by kpv: Fix viewElements api change in formatter.

diff --git a/src/Plugin/Field/FieldFormatter/LeafletDefaultFormatter.php b/src/Plugin/Field/FieldFormatter/LeafletDefaultFormatter.php
index 989e6ba..72be874 100644
--- a/src/Plugin/Field/FieldFormatter/LeafletDefaultFormatter.php
+++ b/src/Plugin/Field/FieldFormatter/LeafletDefaultFormatter.php
@@ -239,7 +239,7 @@ class LeafletDefaultFormatter extends FormatterBase {
    *
    * This function is called from parent::view().
    */
-  public function viewElements(FieldItemListInterface $items) {
+  public function viewElements(FieldItemListInterface $items, $langcode) {
     $settings = $this->getSettings();
     $icon_url = $settings['icon']['icon_url'];