code: public static AuthToken basic( String username, String password )
      {
          return basic( username, password, null );
      }
docs: The basic authentication scheme, using a username and a password.
  @param username this is the "principal", identifying who this token represents
  @param password this is the "credential", proving the identity of the user
  @return an authentication token that can be used to connect to Neo4j
  @see GraphDatabase#driver(String, AuthToken)
  @throws NullPointerException when either username or password is {@code null}