src/vs/workbench/services/workspaces/browser/abstractWorkspaceEditingService.ts/AbstractWorkspaceEditingService/doCopyWorkspaceSettings
class AbstractWorkspaceEditingService:	private doCopyWorkspaceSettings(toWorkspace: IWorkspaceIdentifier, filter?: (config: IConfigurationPropertySchema) => boolean): Promise<void> {
		const configurationProperties = Registry.as<IConfigurationRegistry>(ConfigurationExtensions.Configuration).getConfigurationProperties();
		const targetWorkspaceConfiguration: any = {};
		for (const key of this.configurationService.keys().workspace) {
			if (configurationProperties[key]) {
				if (filter && !filter(configurationProperties[key])) {
					continue;
				}

				targetWorkspaceConfiguration[key] = this.configurationService.inspect(key).workspaceValue;
			}
		}

		return this.jsonEditingService.write(toWorkspace.configPath, [{ path: ['settings'], value: targetWorkspaceConfiguration }], true);
	}