code: function modIsCompleted( id, visited ) {
          var module = modModules[ id ];
          visited = visited || {};
          visited[ id ] = 1;
  
          if ( !module || module.state < MODULE_DEFINED ) {
              return false;
          }
  
          if ( module.state === MODULE_COMPLETED ) {
              return true;
          }
  
          var deps = module.depMs;
          var len = deps.length;
  
          while ( len-- ) {
              var depId = deps[ len ].absId;
              if ( visited[ depId ] ) {
                  continue;
              }
  
              if( !modIsCompleted( depId, visited ) ) {
                  return false;
              }
          }
  
          module.state = MODULE_COMPLETED;
          return true;
      }
docs: 判断模块是否定义完成，即模块与其依赖全部已定义
  
  @ignore
  @param {string} id 模块标识
  @return {boolean}