--- /dev/null
+<?php
+
+namespace Drupal\Core\Entity\Query\Null;
+
+use Drupal\Core\Entity\Query\ConditionBase;
+
+/**
+ * Defines the condition class for the null entity query.
+ */
+class Condition extends ConditionBase {
+
+ /**
+ * {@inheritdoc}
+ */
+ public function compile($query) {
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function exists($field, $langcode = NULL) {
+ return $this->condition($field, NULL, 'IS NOT NULL', $langcode);
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function notExists($field, $langcode = NULL) {
+ return $this->condition($field, NULL, 'IS NULL', $langcode);
+ }
+
+}