code: function get_mod (parsed) {
    var id = parsed.id;
  
    // id -> '@kael/a@1.1.0/b'
    return mods[id] || (mods[id] = {
      // package scope:
      s: parsed.s,
      // package name: 'a'
      n: parsed.n,
      // package version: '1.1.0'
      v: parsed.v,
      // module path: '/b'
      p: parsed.p,
      // module id: 'a@1.1.0/b'
      id: id,
      // package id: 'a@1.1.0'
      k: parsed.k,
      // version map of the current module
      m: {},
      // loading queue
      l: [],
      // If there is no path, it must be a main entry.
      // Actually, there will always be a path when defining a module,
      // but `get_mod` method is called when a module has been required,
      // and not loaded and defined.
      // When we `require('foo')`, `foo` must be a main module of a package.
      main: !parsed.p
      // map: {Object} The map of aliases to real module id
    });
  }
docs: Create a mod