#Fill to the line!

Given input consisting of the characters `_`, <code> </code>, and newline, fill the empty space up to the line!

**Example:**

I will use `#` as the filler character in the example.

    1. Input
            
            
    ________
            
            
            
    2. Fill up to the line, but not above.
            
            
    ________
    ########
    ########
    ########

Test cases coming soon.