Provide summary metrics on size and svtype for a SV call.

def _summarize_call(parts):
    """Provide summary metrics on size and svtype for a SV call.
    """
    svtype = [x.split("=")[1] for x in parts[7].split(";") if x.startswith("SVTYPE=")]
    svtype = svtype[0] if svtype else ""
    start, end = _get_start_end(parts)
    return {"svtype": svtype, "size": int(end) - int(start)}