code: def insert_bytes(fobj, size, offset, BUFFER_SIZE=2 ** 16):
      
  
      if size < 0 or offset < 0:
          raise ValueError
  
      fobj.seek(0, 2)
      filesize = fobj.tell()
      movesize = filesize - offset
  
      if movesize < 0:
          raise ValueError
  
      resize_file(fobj, size, BUFFER_SIZE)
  
      if mmap is not None:
          try:
              mmap_move(fobj, offset + size, offset, movesize)
          except mmap.error:
              fallback_move(fobj, offset + size, offset, movesize, BUFFER_SIZE)
      else:
          fallback_move(fobj, offset + size, offset, movesize, BUFFER_SIZE)
docs: Insert size bytes of empty space starting at offset.
  
      fobj must be an open file object, open rb+ or
      equivalent. Mutagen tries to use mmap to resize the file, but
      falls back to a significantly slower method if mmap fails.
  
      Args:
          fobj (fileobj)
          size (int): The amount of space to insert
          offset (int): The offset at which to insert the space
      Raises:
          IOError