code: private @CheckForNull HashedToken searchMatch(@Nonnull String plainSecret) {
          byte[] hashedBytes = plainSecretToHashBytes(plainSecret);
          for (HashedToken token : tokenList) {
              if (token.match(hashedBytes)) {
                  return token;
              }
          }
          
          return null;
      }
docs: Search in the store if there is a matching token that has the same secret.
  @return {@code null} iff there is no matching token