public function loadAndMerge(string $filename)
  {
    # Attempt to load config file
    if ( \file_exists($filename) ) {
      # Set filename
      $this->filename = $filename;
      # Load the config
      $configArray = \json_decode( \file_get_contents($filename), true);
      if ($configArray) {
        // $configArray = $this->array_change_key_case_recursive($configArray); // Lowercase the keys
        # Merge the Config with existing config
        $this->confValues = \array_replace_recursive($this->confValues, $configArray);

      } else {
        throw new SpinException('Invalid JSON file "'.$filename.'"');

      }

    }

    return $this;
  }