code: function findModulePath(request, parent) {
    var mainScriptDir = path.dirname(Module._resolveFilename(request, parent));
    var resolvedModule = Module._resolveLookupPaths(request, parent);
    var paths = resolvedModule[1];
    for (var i = 0, PL = paths.length; i < PL; i++) {
      if (mainScriptDir.indexOf(paths[i]) === 0) {
        return path.join(paths[i], request.replace('/', path.sep));
      }
    }
    return null;
  }
docs: Determines the path at which the requested module will be loaded given
  the provided parent module.
  
  @param {string} request The name of the module to be loaded.
  @param {object} parent The module into which the requested module will be loaded.