anchor.diff:    !! dimension
     !! @param link_from is the name of another trajectory from which the time can be copied
     !! @param compress Switch to toggle SZIP compression.
  -  subroutine h5md_add_trajectory_data(file_id, trajectory_name, N, D, ID, group_name, species_react, link_from, compress_in)
  +  subroutine h5md_add_trajectory_data(file_id, trajectory_name, N, D, ID, group_name, species_react, link_from, compress)
       integer(HID_T), intent(in) :: file_id
       character(len=*), intent(in) :: trajectory_name
       integer, intent(in) :: N, D
  
positive.code:        stop
      end if
      
      if (present(compress_in)) then
         compress = compress_in
      else
         compress = .false.
      end if
  
      if (present(group_name)) then
  
negative.code: 
      call h5screate_simple_f(rank, dims, s_id, h5_error, max_dims)
      call h5pcreate_f(H5P_DATASET_CREATE_F, plist, h5_error)
      if (compress_var) then
         call h5zfilter_avail_f(H5Z_FILTER_SZIP_F,sz_avail, h5_error)
         if (.not.sz_avail) stop 'SZIP filter not available'
         CALL h5zget_filter_info_f(H5Z_FILTER_SZIP_F, filter_info, h5_error)
  