0.6.0 assert is a function but not in expresso

[nalply]

assert() is same as assert.ok().

nalp@muse:~$ node -v; node -e 'require("assert")(false)'
v0.5.10

assert.js:104
  throw new assert.AssertionError({
        ^
AssertionError: false == true
    at Object.<anonymous> (eval at <anonymous> (eval:1:75))
    at Object.<anonymous> (eval:1:63)
    at Module._compile (module.js:432:26)
    at startup (node.js:84:14)
    at node.js:534:3

but in expresso it's not so.