code: function defineGlobalVars(runtimeConfig, isDebug) {
      const globals = Object.assign({}, runtimeConfig.globals, {
          APP_DEBUG_MODE: isDebug || !!runtimeConfig.debuggable
      })
  
      return new webpack.DefinePlugin(globals)
  }
docs: define globals variables for injecting them into source scope
  @param runtimeConfig
  @param isDebug
  @returns {object}