def METHOD_NAME(self, slhex, nfull):
    r"""Extend the element of list (slhex) to the length (nfull)."""
    nfull = int(nfull)
    n = len(slhex[0])
    dn = (nfull // 4) - n
    ds = "0" * int(dn)
    return [ds + s for s in slhex]