code: protected function arrayToTabList(array $array, array $skipKeys=array(), $indentationLevel = 1) {
          $output = '';
          foreach($array as $key => $value) {
              if (in_array($key, $skipKeys, true)) {
                  continue;
              }
      
              $output .= $this->tabsForIndentation($indentationLevel);
      
              if (!is_array($value)) {
                  if (!is_int($key)) {
                      $output .= ucfirst($key) . ":\n";
                      $output .= $this->tabsForIndentation($indentationLevel+1);
                  }
                  $output .= $value . "\n";
              }
              else {
                  $output .= ucfirst($key) . ":\n";
                  $output .= $this->arrayToTabList($value, $skipKeys, $indentationLevel+1);
              }
          }
      
          return $output;
      }
docs: convert nested array to tab indented list
  
  @param array $array
  @param array $skipKeys
  @param int $indentationLevel
  @return string