@Override
        public InputStream getInputStream() {
            throw new AssertionError("HEAD request should not read input stream");
        }

        @Override
        public InputStream getErrorStream() {
            throw new AssertionError("HEAD request should not read error stream");
        }

        @Override
        public Map<String, List<String>> getHeaderFields() {

            return null;
        }

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

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

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

        @Override

    @Override
    public boolean usingProxy() {
        return connection.usingProxy();
    }

    @Override
    public InputStream getErrorStream() {
        try {
            handshake();
        } catch (final IOException ex) {}
        return connection.getErrorStream();
    }

    private int parseResponseCode() throws IOException {
        try {

            return null;
        }

        @Override
        public java.io.InputStream getInputStream() {
            return null;
        }

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

    private static class TestInputStreamThread extends InputStreamThread {
        private final String output;

            return null;
        }

        @Override
        public java.io.InputStream getInputStream() {
            return null;
        }

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

    // Mock FessConfig implementation
    private class MockFessConfig extends TestFessConfig {
        private static final long serialVersionUID = 1L;

        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);
    }

                    Thread out = new Thread(new StreamGobbler(process.getInputStream(), shellContext.writer));
                    Thread err = new Thread(new StreamGobbler(process.getErrorStream(), shellContext.logger::error));
                    out.start();
                    err.start();
                    int exitCode = process.waitFor();
                    out.join();
                    err.join();

                when(conn.getHeaderField(index++)).thenReturn(entry.getValue().get(0));
            }
        }

        if (code >= 400 && stream != null) {
            when(conn.getErrorStream()).thenReturn(stream);
        } else if (stream != null) {
            when(conn.getInputStream()).thenReturn(stream);
        }
    }

    /**

                    }
                });
                CommonPoolUtil.execute(() -> {
                    try {
                        CloseableUtil.closeQuietly(p.getErrorStream());
                    } catch (final Exception e) {
                        logger.warn("Could not close a process error stream.", e);
                    }
                });