Write sequences predicted to be Rabs as a fasta file.

        :return: Number of written sequences
        :rtype: int

def write(self):
        """Write sequences predicted to be Rabs as a fasta file.

        :return: Number of written sequences
        :rtype: int
        """

        rabs = [x.seqrecord for x in self.gproteins.values() if x.is_rab()]
        return SeqIO.write(rabs, self.tmpfname + '.phase2', 'fasta')