Creating custom Simscape components in two-phase fluid domain

Flow resistance simscape component in two-phase fluid domain uses function <foundation.two_phase_fluid.normalized_internal_energy> - see below. Where I can find this and other two-phase fluid domain functions for building custom simscape blocks?

Thank you in advance,

% Normalized internal energy for inflow

unorm_A_in = foundation.two_phase_fluid.normalized_internal_energy(A.u, p_A, ...

A.u_min, A.u_max, A.p_TLU, A.u_sat_liq_TLU, A.u_sat_vap_TLU);

unorm_B_in = foundation.two_phase_fluid.normalized_internal_energy(B.u, p_B, ...

A.u_min, A.u_max, A.p_TLU, A.u_sat_liq_TLU, A.u_sat_vap_TLU);