Add specific type hints and docblocks for Quote\Address\Total

Author: schmengler

app/code/Magento/Quote/Model/Quote.php

@@ -1944,7 +1944,7 @@ public function collectTotals()
     /**
      * Get all quote totals (sorted by priority)
      *
-     * @return array
+     * @return Address\Total[]
      */
     public function getTotals()
     {

app/code/Magento/Quote/Model/Quote/Address/Total.php

@@ -5,6 +5,9 @@
  */
 namespace Magento\Quote\Model\Quote\Address;
 
+/**
+ * @method string getCode()
+ */
 class Total extends \Magento\Framework\DataObject
 {
     /**

app/code/Magento/Quote/Model/Quote/TotalsReader.php

@@ -35,7 +35,7 @@ public function __construct(
     /**
      * @param \Magento\Quote\Model\Quote $quote
      * @param array $total
-     * @return array
+     * @return Total[]
      */
     public function fetch(\Magento\Quote\Model\Quote $quote, array $total)
     {
@@ -62,7 +62,7 @@ public function fetch(\Magento\Quote\Model\Quote $quote, array $total)
 
     /**
      * @param array $total
-     * @return Total|array
+     * @return Total|Total[]
      */
     protected function convert($total)
     {
@@ -85,10 +85,10 @@ protected function convert($total)
 
     /**
      * @param Total $totalInstance
-     * @param array $output
-     * @return array
+     * @param Total[] $output
+     * @return Total[]
      */
-    protected function merge($totalInstance, $output)
+    protected function merge(Total $totalInstance, $output)
     {
         if (array_key_exists($totalInstance->getCode(), $output)) {
             $output[$totalInstance->getCode()] = $output[$totalInstance->getCode()]->addData(