Who is Kashmira and Boman from Swimming Lessons and what is their importance?

In "The Paying Guests," Kashmira and Boman are a young married couple who rent the ground floor flat in B Block of the Firozsha Baag apartment complex. To cut costs while they have only one child, they illegally and against advice sublet the kitchen and one bedroom to an aged Parsi couple, Khorshedbai and Ardeasar. Things go well for 18 months, until Kashmira and Boman try to break the agreement when they find they are expecting a second child. Kashmira wants to talk out the eviction peacefully, but Boman insists they consult lawyers. They are defeated in court and suffer Khorshedbai's daily torment, strewing garbage outside their door, until the baby is born and Khorshedbai abducts it and is committed to a mental asylum.