joinHelper(10, 0, 20);
    joinHelper(0, 10, 20);
    joinHelper(10, 20, 0);
    joinHelper(10, 20, 1);
    joinHelper(1, 1, 1, 1, 1, 1, 1, 1);
    joinHelper(1, 0, 1, 0, 1, 0, 1, 0);
  }

  public void testOnlyOneOpen() throws Exception {
    ByteSource source = newByteSource(0, 50);
    int[] counter = new int[1];
    ByteSource checker =
        new ByteSource() {
          @Override

import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * @author ricebin
 */
@NullUnmarked
public class MultiReaderTest extends TestCase {

  public void testOnlyOneOpen() throws Exception {
    String testString = "abcdefgh";
    CharSource source = newCharSource(testString);
    int[] counter = new int[1];
    CharSource reader =
        new CharSource() {
          @Override

    joinHelper(10, 0, 20);
    joinHelper(0, 10, 20);
    joinHelper(10, 20, 0);
    joinHelper(10, 20, 1);
    joinHelper(1, 1, 1, 1, 1, 1, 1, 1);
    joinHelper(1, 0, 1, 0, 1, 0, 1, 0);
  }

  public void testOnlyOneOpen() throws Exception {
    ByteSource source = newByteSource(0, 50);
    int[] counter = new int[1];
    ByteSource checker =
        new ByteSource() {
          @Override