throw new fortuna.EntropyException(`entropyFxn needs to return either a string or array of length ${fortuna.entropySz} but you gave me ${typeof entropyTestValue} of length ${entropyTestValue.length}.`);
^
TypeError: Cannot read property 'length' of undefined
at Object.fortuna.init (/home/spieljs/develop/random/node_modules/javascript-fortuna/lib/fortuna.js:40:196)
at Object.<anonymous> (/home/spieljs/develop/random/testSi.js:31:9)
at Module._compile (module.js:652:30)
at Object.Module._extensions..js (module.js:663:10)
at Module.load (module.js:565:32)
at tryModuleLoad (module.js:505:12)
at Function.Module._load (module.js:497:3)
at Function.Module.runMain (module.js:693:10)
at startup (bootstrap_node.js:188:16)
at bootstrap_node.js:609:3
I get a error when I try the advance example.