function blobToBinaryString(blob) {
        return new Promise(function (resolve, reject) {
            var reader = new FileReader();
            var hasBinaryString = typeof reader.readAsBinaryString === 'function';
            reader.onloadend = function () {
                var result = reader.result || '';
                if (hasBinaryString) {
                    return resolve(result);
                }
                resolve(arrayBufferToBinaryString(result));
            };
            reader.onerror = reject;
            if (hasBinaryString) {
                reader.readAsBinaryString(blob);
            }
            else {
                reader.readAsArrayBuffer(blob);
            }
        });
    }
Convert a <code>Blob</code> to a binary string.

Example:

```js
blobUtil.blobToBinaryString(blob).then(function (binaryString) {
  // success
}).catch(function (err) {
  // error
});
```

@param blob
@returns Promise that resolves with the binary string