createCsvStreamRead readStream set to undefined?

[dereke]

This is more of a question than an issue. This method (createCsvStreamReader) sets the readStream to undefined if no options are passed through:

csv.createCsvStreamReader = function(readStream, options) {
    if (options === undefined && typeof readStream === 'object') {
        options = readStream;
        readStream = undefined;
    }
    options = options || {};
    if (readStream) readStream.setEncoding(options.encoding || 'utf8');
    return new CsvReader(readStream, options);
};

It seem like really strange behaviour, and my reader was not receiving any events because of this. Is this actually intended behaviour?