<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def is_cpat_compatible(gtf):
 """ CPAT needs some transcripts annotated with protein coding status to work properly """

    if not gtf:
        return False
    db = get_gtf_db(gtf)
    pred = lambda biotype: biotype and biotype == "protein_coding"
    biotype_lookup = _biotype_lookup_fn(gtf)
    if not biotype_lookup:
        return False
    db = get_gtf_db(gtf)
    for feature in db.all_features():
        biotype = biotype_lookup(feature)
        if pred(biotype):
            return True
    return False