Called in the inner loop of `generate_contact_vectors!`, this function removes the degree corresponding to kth entry of index_lists, replaces it with another randomly sampled degree, and returns `csum` adjusted to the new samples.
Called in the inner loop of `generate_contact_vectors!`, this function removes the degree corresponding to kth entry of index_lists, replaces it with another randomly sampled degree, and returns `csum` adjusted to the new samples.