return null;
        }

        @Override
        public InputStream getInputStream() {
            return inputStream;
        }

        @Override
        public InputStream getErrorStream() {
            return null;
        }

        @Override
        public int waitFor() throws InterruptedException {
            return 0;
        }

        @Override

        ProcessBuilder pb = new ProcessBuilder(cmd);
        Process p = pb.start();
        Future<String> outFuture = readStreamAsync(p.getInputStream());
        Future<String> errFuture = readStreamAsync(p.getErrorStream());
        int code = p.waitFor();
        String out = outFuture.get();
        String err = errFuture.get();
        return new ExecResult(code, out, err);
    }

        Process process = pb.start();

        Future<String> stdoutFuture = readStreamAsync(process.getInputStream());
        Future<String> stderrFuture = readStreamAsync(process.getErrorStream());

        int returnCode = process.waitFor();
        String stdout = stdoutFuture.get();
        String stderr = stderrFuture.get();
        return new ExecResult(stdout, stderr, returnCode);
    }

        ProcessBuilder pb = new ProcessBuilder(cmd);
        Process p = pb.start();
        String out = readFully(p.getInputStream());
        String err = readFully(p.getErrorStream());
        int code = p.waitFor();
        return new ExecResult(code, out, err);
    }

    private static String readFully(InputStream in) throws IOException {