assertTrue(source.wasStreamOpened());
    assertFalse(source.wasStreamClosed());

    StringWriter writer = new StringWriter();
    char[] buf = new char[64];
    int read;
    while ((read = reader.read(buf)) != -1) {
      writer.write(buf, 0, read);
    }
    reader.close();
    writer.close();

    assertTrue(source.wasStreamClosed());
    assertEquals(STRING, writer.toString());
  }

      // The default implementation of Reader#read(CharBuffer) allocates a
      // temporary char[], so we call Reader#read(char[], int, int) instead.
      int read = (reader != null) ? reader.read(buf, 0, buf.length) : readable.read(cbuf);
      if (read == -1) {
        lineBuf.finish();
        break;
      }
      lineBuf.add(buf, 0, read);
    }
    return lines.poll();
  }

    ByteSource source = out.asByteSource();

    out.write(data);
    assertTrue(Arrays.equals(data, source.read()));

    out.reset();
    assertTrue(Arrays.equals(new byte[0], source.read()));

    out.write(data);
    assertTrue(Arrays.equals(data, source.read()));

    out.close();
  }

  private static boolean isAndroid() {

    InputStream in = url.openStream();
    try {
      OutputStream out = new FileOutputStream(file);
      try {
        byte[] buf = new byte[4096];
        for (int read = in.read(buf); read != -1; read = in.read(buf)) {
          out.write(buf, 0, read);
        }
      } finally {
        out.close();
      }
    } finally {
      in.close();
    }
  }

  @CanIgnoreReturnValue

      InputStream in = new FileInputStream(file);
      ByteArrayOutputStream out = new ByteArrayOutputStream();
      byte[] buffer = new byte[100];
      int read;
      while ((read = in.read(buffer)) != -1) {
        out.write(buffer, 0, read);
      }
      return out.toByteArray();
    }
  }

  private static class FileCharSourceFactory extends FileFactory implements CharSourceFactory {

 */

package com.google.common.io;

import static com.google.common.io.TestOption.CLOSE_THROWS;
import static com.google.common.io.TestOption.OPEN_THROWS;
import static com.google.common.io.TestOption.READ_THROWS;
import static com.google.common.io.TestOption.WRITE_THROWS;
import static org.junit.Assert.assertThrows;

import com.google.common.collect.ImmutableList;
import java.io.IOException;
import java.io.StringReader;

 * An extension of {@code DataInput} for reading from in-memory byte arrays; its methods offer
 * identical functionality but do not throw {@link IOException}.
 *
 * <p><b>Warning:</b> The caller is responsible for not attempting to read past the end of the
 * array. If any method encounters the end of the array prematurely, it throws {@link
 * IllegalStateException} to signify <i>programmer error</i>. This behavior is a technical violation

    assertEquals(-1, ArbitraryInstances.get(InputStream.class).read());
    assertEquals(-1, ArbitraryInstances.get(ByteArrayInputStream.class).read());
    assertEquals(-1, ArbitraryInstances.get(Readable.class).read(CharBuffer.allocate(1)));
    assertEquals(-1, ArbitraryInstances.get(Reader.class).read());
    assertEquals(-1, ArbitraryInstances.get(StringReader.class).read());
    assertEquals(0, ArbitraryInstances.get(Buffer.class).capacity());

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    final Supplier<T> delegate;
    transient volatile boolean initialized;
    // "value" does not need to be volatile; visibility piggy-backs
    // on volatile read of "initialized".
    @CheckForNull transient T value;

    MemoizingSupplier(Supplier<T> delegate) {
      this.delegate = checkNotNull(delegate);
    }

    @Override
    @ParametricNullness