var path = require('node-path-extras');
  console.log(path.contains('/a', '/a/b')); // true

  var path = require('node-path-extras');
  console.log(path.within('/a/b', '/a')); // true

  var path = require('node-path-extras');
  console.log(path.along('/a/b/c', '/a/b', '/a/b/c/d')); // true

  var path = require('node-path-extras');
  console.log(path.isRelative('../a')); // true
  console.log(path.isRelative('/a'));   // false

  var path = require('node-path-extras');
  console.log(path.isAbsolute('../a')); // false
  console.log(path.isAbsolute('/a'));   // true

  // for windows
  console.log(path.isAbsolute('c:\a')); // true

  var path = require('node-path-extras');
  console.log(path.unique(['/a/b', '/a', '/c'])); // ['/a', '/c']