ReleasableInputStream extends InputStream { @Override public boolean markSupported() { return delegate.markSupported(); } ReleasableInputStream(InputStream delegate, Runnable onClose); @Override int read(); @Override int read(byte[] bytes); @Override int read(byte[] bytes, int i, int i1); @Override long skip(long l); @Override int available(); @Override void close(); @Override void mark(int i); @Override void reset(); @Override boolean markSupported();  }
@Test public void markSupported() throws Exception { releasableInputStream.markSupported(); assertFalse(wasCalled.get()); }