How @bem/sdk.config works?

const mockfs = require('mock-fs'); const { stripIndent } = require('common-tags'); const config = require("@bem/sdk.config")(); mockfs({ '.bemrc': stripIndent` module.exports = { root: true, levels: { 'common.blocks': {}, 'desktop.bundles': {} }, modules: { 'bem-tools': { plugins: { create: { templates: { 'bemdecl.js': '.bem/templates/bemdecl.js', }, techs: ['css', 'js'], levels: { 'desktop.bundles': { techs: [ 'bemdecl.js', ], }, 'common.blocks': { default: true } } } } } } }` }); const conf = await config.get(); conf;