@classmethod<EOL><INDENT>def parse(cls, fptr, offset, length):<DEDENT>
num_bytes = offset + length - fptr.tell()<EOL>read_buffer = fptr.read(num_bytes)<EOL>num_fragments, = struct.unpack_from('<STR_LIT>', read_buffer, offset=<NUM_LIT:0>)<EOL>lst = struct.unpack_from('<STR_LIT:>>' + '<STR_LIT>' * num_fragments,<EOL>read_buffer,<EOL>offset=<NUM_LIT:2>)<EOL>frag_offset = lst[<NUM_LIT:0>::<NUM_LIT:3>]<EOL>frag_len = lst[<NUM_LIT:1>::<NUM_LIT:3>]<EOL>data_reference = lst[<NUM_LIT:2>::<NUM_LIT:3>]<EOL>return cls(frag_offset, frag_len, data_reference,<EOL>length=length, offset=offset)<EOL>
Parse JPX free box.

        Parameters
        ----------
        f : file
            Open file object.
        offset : int
            Start position of box in bytes.
        length : int
            Length of the box in bytes.

        Returns
        -------
        FragmentListBox
            Instance of the current fragment list box.