public boolean remove(@CheckForNull Object o) {
      if (o instanceof Entry) {
        Entry<?, ?> entry = (Entry<?, ?>) o;
        if (unfiltered.containsKey(entry.getKey())
            // if this holds, then we know entry.getKey() is a K
            && keyPredicate.apply((K) entry.getKey())) {
          return unfiltered.remove(entry.getKey(), entry.getValue());
        }
      }
      return false;
    }
  }

 * retrieval operations obtain elements at the head of the queue.
 *
 * <p>This is a classic &quot;bounded buffer&quot;, in which a fixed-sized array holds elements
 * inserted by producers and extracted by consumers. Once created, the capacity cannot be increased.
 * Attempts to {@code put} an element into a full queue will result in the operation blocking;

   * CASes when performing an update operation (see method
   * retryUpdate). Upon a collision, if the table size is less than
   * the capacity, it is doubled in size unless some other thread
   * holds the lock. If a hashed slot is empty, and lock is
   * available, a new Cell is created. Otherwise, if the slot
   * exists, a CAS is tried.  Retries proceed by "double hashing",

    assertThat(lazyStackTrace(e)).containsExactly((Object[]) originalStackTrace).inOrder();

    assertThrows(UnsupportedOperationException.class, () -> lazyStackTrace(e).set(0, null));

    // Now we test a property that holds only for the lazy implementation.

    if (!lazyStackTraceIsLazy()) {
      return;
    }

    e.setStackTrace(new StackTraceElement[0]);

    assertThat(lazyStackTrace(e)).containsExactly((Object[]) originalStackTrace).inOrder();

    assertThrows(UnsupportedOperationException.class, () -> lazyStackTrace(e).set(0, null));

    // Now we test a property that holds only for the lazy implementation.

    if (!lazyStackTraceIsLazy()) {
      return;
    }

    e.setStackTrace(new StackTraceElement[0]);

 *
 * <h4>Manually closing</h4>
 *
 * If you want to close the captured objects manually, after you've used the final result, call
 * {@link #finishToValueAndCloser(ValueAndCloserConsumer, Executor)} to get an object that holds the
 * final result. You then call {@link ValueAndCloser#closeAsync()} to close the captured objects.
 *
 * <pre>{@code
 *     ClosingFuture.submit(

 * call {@link #finish} at the end of stream.
 *
 * @author Chris Nokleberg
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
abstract class LineBuffer {
  /** Holds partial line contents. */
  private StringBuilder line = new StringBuilder();
  /** Whether a line ending with a CR is pending processing. */
  private boolean sawReturn;

  /**