RandomAccessFileInputStream extends InputStream { @Override public boolean markSupported() { return true; } RandomAccessFileInputStream(File file);  RandomAccessFileInputStream(File file, long rangeOffset, long rangeLength); void setRange(long rangeOffset, long rangeLength); @Override int available(); long getPosition(); @Override void close(); @Override int read(); @Override int read(byte[] b, int off, int len); @Override int read(byte[] b); @Override long skip(long n); @Override boolean markSupported(); @Override void mark(int readlimit); @Override void reset(); long length();  }
@Test public void testMarkSupported() { Assert.assertTrue(stream.markSupported()); }