docs: def similarity(self, self_start, self_end, other_start, other_end, other):
      """
        Compute the number of matching bases in the subsequences self[start, end]
        and other[o_start, o_end]. Note that the subsequences must be the same
        length.
  
        :param self_start:  start index for sub-sequence in self
        :param self_end:    end index for sub-sequence in self
        :param other_start: start index for subsequence in other sequence
        :param other_end:   end index for subsequence in other sequence
        :param other:       other sequence to compare to this.
      """
      assert(self_end - self_start == other_end - other_start)
      count = 0
      for i in range(0, self_end - self_start + 1):
        if (self.sequenceData[self_start + i] ==
           other.sequenceData[other_start + i]):
          count += 1
      return count