I am trying to expand  a rational function that is in the form:

P(z) = (1 + z⁻¹)² (1 + z)²· (r1z + r0 + r1z⁻¹)

to the form:

P(z) = r1z³ + (4r1 + r0)z² + (7r1 + 4r0)z + (8r1 + 6r0)

+(7r1 + 4r0)z⁻¹ + (4r1 + r0)z⁻² + r1z⁻³

Can someone show me how to do this please?