Change the visibility of the internal methods from protected to private

Author: stevegrunwell

src/MarkupAssertionsTrait.php

@@ -222,7 +222,7 @@ public function assertElementNotRegExp($regexp, $selector = '', $markup = '', $m
      *
      * @return Crawler
      */
-    protected function executeDomQuery($markup, $query)
+    private function executeDomQuery($markup, $query)
     {
         $dom = new Crawler($markup);
 
@@ -240,7 +240,7 @@ protected function executeDomQuery($markup, $query)
      *
      * @return string A XPath attribute query selector.
      */
-    protected function flattenAttributeArray(array $attributes)
+    private function flattenAttributeArray(array $attributes)
     {
         if (empty($attributes)) {
             throw new RiskyTestError('Attributes array is empty.');
@@ -268,7 +268,7 @@ protected function flattenAttributeArray(array $attributes)
      *
      * @return string The concatenated innerHTML of any matched selectors.
      */
-    protected function getInnerHtmlOfMatchedElements($markup, $query)
+    private function getInnerHtmlOfMatchedElements($markup, $query)
     {
         $results  = $this->executeDomQuery($markup, $query);
         $contents = [];