code: public List<User> findAllUsers() {
          List<User> list = new ArrayList<>();
          List<String> usernames;
          try {
              usernames = readLines(usersFile);
          } catch (IOException e) {
              throw new FileBasedRuntimeException(e);
          }
          for (String username : usernames) {
              if (StringUtils.isNotBlank(username)) {
                  list.add(new User(username));
              }
          }
          
          return list;
      }
docs: Finds all the available users.
  
  @return the list of available users