code: public static HttpHeaders createHeaders(String username, String password) {
          if (username == null || username.isEmpty()) {
              return new HttpHeaders();
          }
          String auth = username + ":" + password;
          byte[] encodedAuth = Base64.getEncoder().encode(auth.getBytes(StandardCharsets.UTF_8));
          String authHeader = "Basic " + new String(encodedAuth);
  
          HttpHeaders result =  new HttpHeaders();
          result.add(HttpHeaders.AUTHORIZATION, authHeader);
          return result;
      }
docs: With the given {@code username} and {@code password} create a Base64 encoded valid
  http BASIC schema authorization header, and return it within a {@link HttpHeaders}
  object.
  
  @param username The BASIC auth username
  @param password The BASIC auth password
  @return The HttpHeaders object containing the Authorization Header