'Sets the object to the state needed for the first read.'

def set_initial_state(self):

    self._f.seek(0)
    self._compressor = compressobj(self.compresslevel, zlib.DEFLATED, (- zlib.MAX_WBITS), zlib.DEF_MEM_LEVEL, 0)
    self.done = False
    self.first = True
    self.crc32 = 0
    self.total_size = 0
