Issue #3378657 by dineshkumarbollu, gorkagr, smustgrave: Duplicate declaration...

      $elements = $this->formMultipleElements($items, $form, $form_state);

    }

    // Allow modules to alter the field multi-value widget form element.

    // This hook can also be used for single-value fields.

    $context = [

      'form' => $form,

      'widget' => $this,

      'items' => $items,

      'default' => $this->isDefaultValueWidget($form_state),

    ];

    // Populate the 'array_parents' information in $form_state->get('field')

    // after the form is built, so that we catch changes in the form structure

    // performed in alter() hooks.