code: function FunctionStream(func, options) {
  	options = !options ? {} : options;
  
  	options.objectMode = true;
  	Readable.call(this, options);
  
  	this._functionFunc = func;
  	this._inGeneratorLoop = false;
  	this._generatorHasEnded = false;
  }
docs: FunctionStream takes a function with a callback and pushes its output on read
  NOTE: objectMode will always be true
  
  @class FunctionStream
  @constructor
  @extends Readable
  @param {Function} func - Function to generate stream entries
  @param {Object} [options] - Stream options object