er field config

<code>
+++ b/core/modules/field/tests/src/Kernel/Migrate/d6/MigrateFieldTest.php
@@ -84,36 +84,41 @@ public function testFields() {
+    // Test a node reference field.
+    $field_storage = FieldStorageConfig::load('node.field_company');
+    $this->assertInstanceOf(FieldStorageConfig::class, $field_storage);
+    $this->assertSame('node', $field_storage->getSetting('target_type'));
</code>

This is the ER field tests that I found.