> var assert = require('assert-plus');
undefined
> var buf = new Buffer(1);
undefined
> assert.buffer(buf);
undefined
> assert.optionalBuffer(buf);
AssertionError: buffer (buffer) is required
at repl:1:8
at REPLServer.self.eval (repl.js:110:21)
at repl.js:249:20
at REPLServer.self.eval (repl.js:122:7)
at Interface.<anonymous> (repl.js:239:12)
at Interface.emit (events.js:95:17)
at Interface._onLine (readline.js:203:10)
at Interface._line (readline.js:532:8)
at Interface._ttyWrite (readline.js:761:14)
at ReadStream.onkeypress (readline.js:100:10)