### Question:
DeferredFileBody implements RawDataBody, SizeAware { @Override public void writeTo(OutputStream out) throws IOException, MessagingException { InputStream inputStream = getInputStream(); IOUtils.copy(inputStream, out); } DeferredFileBody(FileFactory fileFactory, String transferEncoding); @VisibleForTesting  DeferredFileBody(int memoryBackedThreshold, FileFactory fileFactory,
            String transferEncoding); OutputStream getOutputStream(); @Override InputStream getInputStream(); @Override long getSize(); File getFile(); @Override void setEncoding(String encoding); @Override void writeTo(OutputStream out); @Override String getEncoding(); static final int DEFAULT_MEMORY_BACKED_THRESHOLD; }### Answer:
@Test public void withShortData__writeTo__shouldWriteData() throws Exception { writeShortTestData(); ByteArrayOutputStream baos = new ByteArrayOutputStream(); deferredFileBody.writeTo(baos); assertArrayEquals(TEST_DATA_SHORT, baos.toByteArray()); }