code: function initGlobalComponents(appType, componentConf, sourceDir) {
      let {global: globalComponents} = componentConf;
      if (!globalComponents) {
          return;
      }
  
      let result = {};
      Object.keys(globalComponents).forEach(k => {
          let value = globalComponents[k];
          value = value.replace(/^okam\//, BUILTIN_COMPONENTS_PACKAGE_ROOT + appType + '/');
          let isRelMod = value.charAt(0) === '.';
          if (isRelMod) {
              value = pathUtil.join(sourceDir, value);
          }
          result[toHyphen(k)] = {
              isNpmMod: !isRelMod,
              modPath: value
          };
      });
      return result;
  }
docs: Initialize the imported global component definition
  
  @param {string} appType the app type to build
  @param {Object} componentConf the component config
  @param {string} sourceDir the source root directory
  @return {Object}