Method loadUserByUsername

/**
 * Method to get an instance of a user for the given username.
 *
 * @param   string  $username  The username
 *
 * @return  User
 *
 * @since   4.0.0
 */
public function loadUserByUsername(string $username) : User
{
    // Initialise some variables
    $query = $this->db->getQuery(true)->select($this->db->quoteName('id'))->from($this->db->quoteName('#__users'))->where($this->db->quoteName('username') . ' = :username')->bind(':username', $username)->setLimit(1);
    $this->db->setQuery($query);
    return $this->loadUserById((int) $this->db->loadResult());
}