def METHOD_NAME():
    """
    This helps trim the library a bit by excluding rates with
    products with more protons than the endpoint, heavier than the
    endpoint, or with relatively high or low neutron percentages. 
    """
    # Proton number bounds
    Zlo, Zhi = 6, endpoint.Z
    # Nucleon number bounds
    Alo, Ahi = 12, endpoint.A
    # Bounds on A / Z ratio to drop peripheral nuclei
    Rlo, Rhi = 1.69, 2.2
    def limit_products(r):
        meet_conds = \
        (
            (Zlo <= p.Z <= Zhi and
            Alo <= p.A <= Ahi and
            Rlo <= p.A / p.Z <= Rhi and
            (p.N, p.Z) in bintable.energies) or
            (p.Z, p.A) == (1, 1) or
            (p.Z, p.A) == (2, 4)
            for p in r.products
        )
        return all(meet_conds)
    return limit_products