role ]   = $display_name;
		return $this->role_objects[ $role ];
	}

	/**
	 * Removes a role by name.
	 *
	 * @since 2.0.0
	 *
	 * @param string $role Role name.
	 */
	public function remove_role( $role ) {
		if ( ! isset( $this->role_objects[ $role ] ) ) {
			return;
		}

		unset( $this->role_objects[ $role ] );
		unset( $this->role_names[ $role ] );
		unset( $this->roles[ $role ] );

		if ( $this->use_db ) {
			update_option( $this->role_key, $this->roles );
		}

		if ( get_option( 'default_role' ) === $role ) {
			update_option( 'default_role', 'subscriber' );
		}
	}

	/**
	 * Adds a capability to role.
	 *
	 * @since 2.0.0
	 *
	 * @param string $role  Role name.
	 * @param string $cap   Capability name.
	 * @param bool   $grant Optional. Whether role is capable of performing capability.
	 *                      Default true.
	 */
	public function add_cap( $role, $cap, $grant = true ) {
		if ( ! isset( $this->roles[ $role ] ) ) {
			return;
		}

		$this->roles[ $role ]['capabilities'][ $cap ] = $grant;
		if ( $this->use_db ) {
			update_option( $this->role_key, $this->roles );
		}
	}

	/**
	 * Removes a capability from role.
	 *
	 * @since 2.0.0
	 *
	 * @param string $role Role name.
	 * @param string $cap  Capability name.
	 */
	public function remove_cap( $role, $cap ) {
		if ( ! isset( $this->roles[ $role ] ) ) {
			return;
		}

		unset( $this->roles[ $role ]['capabilities'][ $cap ] );
		if ( $this->use_db ) {
			update_option( $this->role_key, $this->roles );
		}
	}

	/**
	 * Retrieves a role object by name.
	 *
	 * @since 2.0.0
	 *
	 * @param string $role Role name.
	 * @return WP_Role|null WP_Role object if found, null if the role does not exist.
	 */
	public function get_role( $role ) {
		if ( isset( $this->role_objects[ $role ] ) ) {
			return $this->role_objects[ $role ];
		} else {
			return null;
		}
	}

	/**
	 * Retrieves a list of role names.
	 *
	 * @since 2.0.0
	 *
	 * @return string[] List of role names.
	 */
	public function get_names() {
		return $this->role_names;
	}

	/**
	 * Determines whether a role name is currently in the list of available roles.
	 *
	 * @since 2.0.0
	 *
	 * @param string $role Role name to look up.
	 * @return bool
	 */
	public function is_role( $role ) {
		return isset( $this->role_names[ $role ] );
	}

	/**
	 * Initializes all of the available roles.
	 *
	 * @since 4.9.0
	 */
	public function init_roles() {
		if ( empty( $this->roles ) ) {
			return;
		}

		$this->role_objects = array();
		$this->role_names   = array();
		foreach ( array_keys( $this->roles ) as $role ) {
			$this->role_objects[ $role ] = new WP_Role( $role, $this->roles[ $role ]['capabilities'] );
			$this->role_names[ $role ]   = $this->roles[ $role ]['name'];
		}

		/**
		 * Fires after the roles have been initialized, allowing plugins to add their own roles.
		 *
		 * @since 4.7.0
		 *
		 * @param WP_Roles $wp_roles A reference to the WP_Roles object.
		 */
		do_action( 'wp_roles_init', $this );
	}

	/**
	 * Sets the site to operate on. Defaults to the current site.
	 *
	 * @since 4.9.0
	 *
	 * @global wpdb $wpdb WordPress database abstraction object.
	 *
	 * @param int $site_id Site ID to initialize roles for. Default is the current site.
	 */
	public function for_site( $site_id = null ) {
		global $wpdb;

		if ( ! empty( $site_id ) ) {
			$this->site_id = absint( $site_id );
		} else {
			$this->site_id = get_current_blog_id();
		}

		$this->role_key = $wpdb->get_blog_prefix( $this->site_id ) . 'user_roles';

		if ( ! empty( $this->roles ) && ! $this->use_db ) {
			return;
		}

		$this->roles = $this->get_roles_data();

		$this->init_roles();
	}

	/**
	 * Gets the ID of the site for which roles are currently initialized.
	 *
	 * @since 4.9.0
	 *
	 * @return int Site ID.
	 */
	public function get_site_id() {
		return $this->site_id;
	}

	/**
	 * Gets the available roles data.
	 *
	 * @since 4.9.0
	 *
	 * @global array $wp_user_roles Used to set the 'roles' property value.
	 *
	 * @return array Roles array.
	 */
	protected function get_roles_data() {
		global $wp_user_roles;

		if ( ! empty( $wp_user_roles ) ) {
			return $wp_user_roles;
		}

		if ( is_multisite() && get_current_blog_id() !== $this->site_id ) {
			remove_action( 'switch_blog', 'wp_switch_roles_and_user', 1 );

			$roles = get_blog_option( $this->site_id, $this->role_key, array() );

			add_action( 'switch_blog', 'wp_switch_roles_and_user', 1, 2 );

			return $roles;
		}

		return get_option( $this->role_key, array() );
	}
}
<br />
<b>Fatal error</b>:  Uncaught Error: Class 'WP_Roles' not found in /home/ocb/public_html/wp-settings.php:627
Stack trace:
#0 /home/ocb/public_html/wp-config.php(77): require_once()
#1 /home/ocb/public_html/wp-load.php(50): require_once('/home/ocb/publi...')
#2 /home/ocb/public_html/wp-blog-header.php(13): require_once('/home/ocb/publi...')
#3 /home/ocb/public_html/index.php(17): require('/home/ocb/publi...')
#4 {main}
  thrown in <b>/home/ocb/public_html/wp-settings.php</b> on line <b>627</b><br />