findPackage(packageName) {
    if (!this.hasEntries) {
      return null;
    } // for speed

    let val;

    if (packageName.startsWith('@')) {
      let parts = packageName.split('/');
      let entry = this.entries[parts[0]]; // scope
      val =
        entry instanceof NodeModulesList
          ? entry.findPackage(parts[1]) // the real name
          : null;
    } else {
      val = this.entries[packageName] || null;
    }

    return val;
  }
Return a PackageInfo object for a given package name (which may include
a scope)

@public
@method findPackage
@param {String} packageName the name (possibly including a scope) of
   the PackageInfo the caller wants returned.
@return the desired PackageInfo if one exists for the given name, else null.