Appends pos1, pos2, etc to the gene_code if needed.

def add_suffixes_to_gene_codes(self):
        """Appends pos1, pos2, etc to the gene_code if needed."""
        out = []
        for gene_code in self.data.gene_codes:
            for sufix in self.make_gene_code_suffixes():
                out.append('{0}{1}'.format(gene_code, sufix))
        return out