Given the following piece of Java code, assuming that the flow of control proceeds to the call to sysIn.readLine$()$ and pauses to wait for a user input from the keyboard, when the user does not type any printable character but just hits "enter", this call to sysIn.readLine$()$ returns and the returning value assigned to fromUser is $\_\_\_\_\_\_\_\_\_$ and the while loop $\_\_\_\_\_\_\_\_\_.$

BufferedReader sysIn $=$ new BufferedReader$($new InputStreamReader$($System$.$in$))$;

String fromUser;

while $(($fromUser $=$ sysIn.readLine$()!=$ null$)\{$

$......$

$\}$