old_contents: var tape = require('tape');
  var mid = require('../lib/mid');
  
  tape('Node ID', function(t){
    var test = 'test/data/mid';
    var test2 = 'test/data/mid2';
    var id = mid(test);
    var id2 = mid(test2);
  
    t.ok(id === mid(test), 'test === id');
    t.ok(id2 === mid(test2), 'test2 === id2');
    t.ok(id !== id2, 'test !== test2');
    t.ok(mid(test) !== mid(test2), 'test !== test2');
    t.end();
  });
  
new_contents: var tape = require('tape');
  var mid = require('../lib/mid');
  
  tape('MID', function(t){
    var test = 'test/data/mid';
    var test2 = 'test/data/mid2';
    var id = mid(test);
    var id2 = mid(test2);
  
    t.ok(id === mid(test), 'test === id');
    t.ok(id2 === mid(test2), 'test2 === id2');
    t.ok(id !== id2, 'test !== test2');
    t.ok(mid(test) !== mid(test2), 'test !== test2');
    t.equal(id.length, 8, 'id length 8');
    t.equal(id2.length, 8, 'id2 length 8');
    t.end();
  });
  
subject: Tweak mid test case