How to use the @theia/workspace/lib/browser.WorkspaceCommands.FILE_DELETE function in @theia/workspace

protected async doDiscard(repository: Repository, change: GitFileChange) {
        // Allow deletion, only iff the same file is not yet in the Git index.
        if (await this.git.lsFiles(repository, change.uri, { errorUnmatch: true })) {
            if (await this.confirm(change.uri)) {
                try {
                    await this.git.unstage(repository, change.uri, { treeish: 'HEAD', reset: 'working-tree' });
                } catch (error) {
                    this.gitErrorHandler.handleError(error);
                }
            }
        } else {
            await this.commandService.executeCommand(WorkspaceCommands.FILE_DELETE.id, new URI(change.uri));
        }
    }

protected async doDiscard(repository: Repository, change: GitFileChange) {
        // Allow deletion, only iff the same file is not yet in the Git index.
        if (await this.git.lsFiles(repository, change.uri, { errorUnmatch: true })) {
            if (await this.confirm(change.uri)) {
                try {
                    await this.git.unstage(repository, change.uri, { treeish: 'HEAD', reset: 'working-tree' });
                } catch (error) {
                    this.gitErrorHandler.handleError(error);
                }
            }
        } else {
            await this.commandService.executeCommand(WorkspaceCommands.FILE_DELETE.id, new URI(change.uri));
        }
        if (this.listContainer) {
            this.listContainer.focus();
        }
    }

const { repository } = this;
        const status = this.getStatus();
        if (!(status && status.changes.some(change => change.uri === uri))) {
            return;
        }
        // Allow deletion, only iff the same file is not yet in the Git index.
        if (await this.git.lsFiles(repository, uri, { errorUnmatch: true })) {
            if (await this.confirm(uri)) {
                try {
                    await this.git.unstage(repository, uri, { treeish: 'HEAD', reset: 'working-tree' });
                } catch (error) {
                    this.gitErrorHandler.handleError(error);
                }
            }
        } else {
            await this.commands.executeCommand(WorkspaceCommands.FILE_DELETE.id, new URI(uri));
        }
    }

registerKeybindings(registry: KeybindingRegistry): void {
        super.registerKeybindings(registry);
        registry.registerKeybinding({
            command: FileNavigatorCommands.REVEAL_IN_NAVIGATOR.id,
            keybinding: 'alt+r'
        });

        registry.registerKeybinding({
            command: WorkspaceCommands.FILE_DELETE.id,
            keybinding: 'del',
            context: NavigatorKeybindingContexts.navigatorActive
        });
        if (isOSX) {
            registry.registerKeybinding({
                command: WorkspaceCommands.FILE_DELETE.id,
                keybinding: 'cmd+backspace',
                context: NavigatorKeybindingContexts.navigatorActive
            });
        }

        registry.registerKeybinding({
            command: WorkspaceCommands.FILE_RENAME.id,
            keybinding: 'f2',
            context: NavigatorKeybindingContexts.navigatorActive
        });

        registry.registerKeybinding({
            command: FileNavigatorCommands.TOGGLE_HIDDEN_FILES.id,
            keybinding: 'ctrlcmd+i',
            context: NavigatorKeybindingContexts.navigatorActive
        });

registerKeybindings(registry: KeybindingRegistry): void {
        super.registerKeybindings(registry);
        registry.registerKeybinding({
            command: FileNavigatorCommands.REVEAL_IN_NAVIGATOR.id,
            keybinding: 'alt+r'
        });

        registry.registerKeybinding({
            command: WorkspaceCommands.FILE_DELETE.id,
            keybinding: 'del',
            context: NavigatorKeybindingContexts.navigatorActive
        });
        if (isOSX) {
            registry.registerKeybinding({
                command: WorkspaceCommands.FILE_DELETE.id,
                keybinding: 'cmd+backspace',
                context: NavigatorKeybindingContexts.navigatorActive
            });
        }

        registry.registerKeybinding({
            command: WorkspaceCommands.FILE_RENAME.id,
            keybinding: 'f2',
            context: NavigatorKeybindingContexts.navigatorActive
        });