Randomization of chain ends when generating random copolymer chains

Hi everyone,

Suppose I have copolymer with A and B monomer units, I want to generate a random copolymer with A and B monomers. I want each polymer chain to be different, and therefore, each polymer chain should have a different chain end combination(A-A,A-B,B-A,B-B). From the documentation, I can not find a way to achieve this as the chain end monomer units needs to be explicitly defined. I would appreciate if anyone could provide me a solution. Thank you in advance.

Sincerely,
Max