def left_overlaps(self, other, min_overlap_size=1):
        """
        Does this VariantSequence overlap another on the left side?
        """

        if self.alt != other.alt:
            # allele must match!
            return False

        if len(other.prefix) > len(self.prefix):
            # only consider strings that overlap like:
            #   self: ppppAssss
            #   other:   ppAsssssss
            # which excludes cases where the other sequence has a longer
            # prefix
            return False
        elif len(other.suffix) < len(self.suffix):
            # similarly, we throw away cases where the other sequence is shorter
            # after the alt nucleotides than this sequence
            return False

        # is the other sequence a prefix of this sequence?
        # Example:
        # p1 a1 s1 = XXXXXXXX Y ZZZZZZ
        # p2 a2 s2 =       XX Y ZZZZZZZZZ
        # ...
        # then we can combine them into a longer sequence
        sequence_overlaps = (
            self.prefix.endswith(other.prefix) and
            other.suffix.startswith(self.suffix)
        )
        prefix_overlap_size = min(len(self.prefix), len(other.prefix))
        suffix_overlap_size = min(len(other.suffix), len(self.suffix))
        overlap_size = (
            prefix_overlap_size + suffix_overlap_size + len(self.alt))

        return sequence_overlaps and overlap_size >= min_overlap_size
Does this VariantSequence overlap another on the left side?