ot::Lowpan::FragmentHeader::IsFragmentHeader() method

TRUE If the header matches the Fragment Header dispatch value. FALSE If the header does not match the Fragment Header dispatch value.

This method checks whether the frame has the minimum required length and that the first byte in header (dispatch byte) matches the Fragment Header dispatch value. It does not fully parse and validate the Fragment Header. `ParseFrom()` method can be used to fully parse and validate the header.