--- /dev/null
+<?php
+
+namespace Drupal\field_test\Plugin\Field\FieldWidget;
+
+/**
+ * Plugin implementation of the 'test_field_widget_multiple' widget.
+ *
+ * The 'field_types' entry is left empty, and is populated through
+ * hook_field_widget_info_alter().
+ *
+ * @see field_test_field_widget_info_alter()
+ *
+ * @FieldWidget(
+ * id = "test_field_widget_multiple_single_value",
+ * label = @Translation("Test widget - multiple - single value"),
+ * multiple_values = FALSE,
+ * weight = 10
+ * )
+ */
+class TestFieldWidgetMultipleSingleValues extends TestFieldWidgetMultiple {
+
+}