### Question:
ClientBlob extends AbstractBlob { @Override public boolean exists() throws IOException { ensureOpen(); return remote.exists(); } ClientBlob(BlobStoreConnection con, StreamManager streamMgr,
                    RemoteBlob remote); @Override URI getCanonicalId(); @Override InputStream openInputStream(); @Override OutputStream openOutputStream(long estSize, boolean overwrite); @Override long getSize(); @Override boolean exists(); @Override void delete(); @Override Blob moveTo(URI blobId, Map<String, String> hints);  }### Answer:
@Test public void testExists() throws IOException { reset(blob); expect(blob.exists()).andReturn(true); replay(blob); assertTrue(cb.exists()); verify(blob); }