code: public CompletableFuture<TransactionEvent> sendTransaction(Collection<? extends ProposalResponse> proposalResponses, Collection<Orderer> orderers, User userContext) {
          return sendTransaction(proposalResponses, createTransactionOptions().orderers(orderers).userContext(userContext));
      }
docs: Send transaction to one of a specified set of orderers with the specified user context.
  IF there are no eventing peers this future returns immediately completed
  indicating that orderer has accepted the transaction only.
  
  @param proposalResponses
  @param orderers
  @return Future allowing access to the result of the transaction invocation.