### Question:
WWWBlob extends AbstractBlob { @Override public OutputStream openOutputStream(long estimatedSize, boolean overwrite) throws IOException { if (!overwrite && exists()) throw new DuplicateBlobException(id); URLConnection con = connect(false, false); OutputStream os = streamManager.manageOutputStream(owner, con.getOutputStream()); exists = true; return os; } WWWBlob(URL url, BlobStoreConnection conn, StreamManager streamManager); @Override long getSize(); @Override InputStream openInputStream(); @Override OutputStream openOutputStream(long estimatedSize, boolean overwrite); @Override boolean exists(); @Override void delete(); @Override Blob moveTo(URI blobId, Map<String, String> hints);  }### Answer:
@Test public void testOpenOutputStream() { try { assertNotNull(blob.openOutputStream(-1, true)); } catch (IOException e) { fail("openOutputStream() failed", e); } }