code: def blat(self, db=None, sequence=None, seq_type="DNA"):
          
          from . blat_blast import blat, blat_all
          assert sequence in (None, "cds", "mrna")
          seq = self.sequence() if sequence is None else ("".join(self.cds_sequence if sequence == "cds" else self.mrna_sequence))
          if isinstance(db, (tuple, list)):
              return blat_all(seq, self.gene_name, db, seq_type)
          else:
              return blat(seq, self.gene_name, db or self.db, seq_type)
docs: make a request to the genome-browsers BLAT interface
          sequence is one of None, "mrna", "cds"
          returns a list of features that are hits to this sequence.