<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def write(self, chunk, offset):
 """ Write chunk to file at specified position Return 0 if OK, else -1 """

        return lib.zfile_write(self._as_parameter_, chunk, offset)