def seek(self, offset, whence=<NUM_LIT:0>):
raise IOError('<STR_LIT>')<EOL>
Set the file's current position, like stdio's C{fseek}.  Not all file
objects support seeking.

@note: If a file is opened in append mode (C{'a'} or C{'a+'}), any seek
    operations will be undone at the next write (as the file position
    will move back to the end of the file).

@param offset: position to move to within the file, relative to
    C{whence}.
@type offset: int
@param whence: type of movement: 0 = absolute; 1 = relative to the
    current position; 2 = relative to the end of the file.
@type whence: int

@raise IOError: if the file doesn't support random access.