code: protected static void setFixedURL(final SpecNode specNode, final String fixedURL, final Set<String> existingFixedUrls) {
          specNode.setFixedUrl(fixedURL);
  
          // Add the fixed url to the processed file names
          existingFixedUrls.add(fixedURL);
      }
docs: Sets the fixed URL property on the node.
  
  @param specNode          The spec node to update.
  @param fixedURL          The fixed url to apply to the node.
  @param existingFixedUrls A list of file names that already exist in the spec.