@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public final class CountingInputStream extends FilterInputStream {

  private long count;
  private long mark = -1;

  /**
   * Wraps another input stream, counting the number of bytes read.
   *
   * @param in the input stream to be wrapped
   */
  public CountingInputStream(InputStream in) {
    super(checkNotNull(in));
  }

import java.io.IOException;
import java.io.InputStream;

/**
 * Unit tests for {@link CountingInputStream}.
 *
 * @author Chris Nokleberg
 */
public class CountingInputStreamTest extends IoTestCase {
  private CountingInputStream counter;

  @Override
  protected void setUp() throws Exception {
    super.setUp();
    counter = new CountingInputStream(new ByteArrayInputStream(new byte[20]));
  }