Inteval of interbase offsets of the affected reference positions for a
    particular variant.

    Parameters
    ----------
    variant : varcode.Variant

    Returns triplet of (base1_location, ref, alt)

def base0_interval_for_variant(variant):
    """
    Inteval of interbase offsets of the affected reference positions for a
    particular variant.

    Parameters
    ----------
    variant : varcode.Variant

    Returns triplet of (base1_location, ref, alt)
    """
    base1_location, ref, alt = trim_variant(variant)
    return base0_interval_for_variant_fields(
        base1_location=base1_location,
        ref=ref,
        alt=alt)