code: public ParseResult parse(String fileContent) {
          ParseResult result = null;
  
          // setup environment and initialize the parser.
          CompilerEnvirons environment = new CompilerEnvirons();
          environment.setLanguageVersion(180);
          environment.setStrictMode(false);
          environment.setRecordingComments(true);
          environment.setAllowSharpComments(true);
          environment.setRecordingLocalJsDocComments(true);
  
          // IMPORTANT: the parser can only be used once!
          Parser parser = new Parser(environment);
          try {
              AstRoot root = parser.parse(new StringReader(fileContent), null, 1);
              result = new ParseResult();
  
              // remove all comments
              result.setContentWithoutComments(root.toSource());
  
              // remove all header comments
              SortedSet<Comment> comments = root.getComments();
              if (comments != null && !comments.isEmpty()) {
                  String headerlessFileContent = removeHeaderComments(fileContent, comments);
                  result.setContentWithoutHeaderComments(headerlessFileContent);
              }
          } catch (Exception e) {
              logger.debug("Error parsing JavaScript file: {}", e.getMessage());
          }
          return result;
      }
docs: Parse the file content and return variants of the file.
  
  @param fileContent to parse
  @return the parsing result