code: public Optional<PartnerAccount> show(long partnerId, long accountId)
      {
          return HTTP.GET(String.format("/v2/partners/%d/accounts/%d", partnerId, accountId), PARTNER_ACCOUNT);
      }
docs: Returns the account with the given id.
  @param partnerId The id of the partner the account belongs to
  @param accountId The id of the account to return
  @return The account