guess if we need to use the gene extent option when making a gffutils
    database by making a tiny database of 1000 lines from the original
    GTF and looking for all of the features

def guess_infer_extent(gtf_file):
    """
    guess if we need to use the gene extent option when making a gffutils
    database by making a tiny database of 1000 lines from the original
    GTF and looking for all of the features
    """
    _, ext = os.path.splitext(gtf_file)
    tmp_out = tempfile.NamedTemporaryFile(suffix=".gtf", delete=False).name
    with open(tmp_out, "w") as out_handle:
        count = 0
        in_handle = utils.open_gzipsafe(gtf_file)
        for line in in_handle:
            if count > 1000:
                break
            out_handle.write(line)
            count += 1
        in_handle.close()
    db = gffutils.create_db(tmp_out, dbfn=":memory:", infer_gene_extent=False)
    os.remove(tmp_out)
    features = [x for x in db.featuretypes()]
    if "gene" in features and "transcript" in features:
        return False
    else:
        return True