anchor.diff:          if (present(error)) then
               error = internal_error
           else
  -            call check(error, att_name)
  +            call check(internal_error, att_name)
           endif
   
           call check( nf90_close(ncid), "closing:"//trim(filename))
  
positive.code:         if (present(error)) then
              error = internal_error
          else
              call check(error, att_name)
          endif
  
          call check( nf90_close(ncid), "closing:"//trim(filename))
  
negative.code:         ! check for errors
          if(status /= nf90_noerr) then
              ! print a useful message
              !$omp critical (print_lock)
              write(*,*) trim(nf90_strerror(status))
              if(present(extra)) then
                  ! print any optionally provided context
                  write(*,*) trim(extra)
              endif
              ! STOP the program execution
              stop "Stopped"
              !$omp end critical (print_lock)
          end if
      end subroutine check
  
  