def test_ubr_holland_4():
"""
Region 4 test.
"""
ubr = cm.ubr_holland(0.01, rho_l, rho_g, sig, mu_l)
assert ubr == approx(0.22, rel=1e-2)
def test_ubr_holland_5():
"""
Region 5 test.
"""
ubr = cm.ubr_holland(0.1, rho_l, rho_g, sig, mu_l)
assert ubr == approx(0.7, rel=1e-2)
def test_ubr_holland_3():
"""
Region 3 test.
"""
ubr = cm.ubr_holland(0.003, rho_l, rho_g, sig, mu_l)
assert ubr == approx(0.3, rel=1e-2)