def METHOD_NAME(self, gid):
    # create a bidirectional gap junction from cell 0 at label "gj_label" to cell 1 at label "gj_label" and back.
    if gid == 0:
        tgt = 1
    elif gid == 1:
        tgt = 0
    else:
        raise RuntimeError("Invalid GID for example.")
    return [arbor.gap_junction_connection((tgt, "gj_label"), "gj_label", 1)]