Magento 2 get Configured Used Children Product Collection

/**
* Returns array of sub-products for specified configurable product
* Result array contains all children for specified configurable product
*
* @param \Magento\Catalog\Model\Product $product
* @param array $requiredAttributeIds Attributes to include in the select; one-dimensional array
* @return ProductInterface[]
*/
public function getUsedProducts($product, $requiredAttributeIds = null)
{
if (!$product->hasData($this->_usedProducts)) {
$collection = $this->getConfiguredUsedProductCollection($product, false, $requiredAttributeIds);
$usedProducts = array_values($collection->getItems());
$product->setData($this->_usedProducts, $usedProducts);
}

    return $product->getData($this->_usedProducts);
}