overwrite_len
Description:
[ Version ( since = "2.14" ) ]
public unowned StringBuilder overwrite_len (size_t pos, string val, ssize_t len)
  public unowned StringBuilder overwrite_len (size_t pos, string val, ssize_t len)
Overwrites part of a string, lengthening it if necessary.
This function will work with embedded nuls.
Parameters:
| this | |
| pos | 
           the position at which to start overwriting  | 
      
| val | 
           the string that will overwrite the this starting at   | 
      
| len | 
           the number of bytes to write from   | 
      
Returns:
| 
           this  |