* for use in test code.
 *
 * <p><b>Do not use this interface</b> for public or protected declarations: it is a fig leaf for
 * bad design, and it does not prevent anyone from using the declaration---and experience has shown
 * that they will. If the method breaks the encapsulation of its class, then its internal
 * representation will be hard to change. Instead, use <a

 * entire "chunk" (of implementation-dependent length) is ready to be hashed.
 *
 * @author Kevin Bourrillion
 * @author Dimitris Andreou
 */
// TODO(kevinb): this class still needs some design-and-document-for-inheritance love
@ElementTypesAreNonnullByDefault
abstract class AbstractStreamingHasher extends AbstractHasher {
  /** Buffer via which we pass data to the hash algorithm (the implementor) */

 * for use in test code.
 *
 * <p><b>Do not use this interface</b> for public or protected declarations: it is a fig leaf for
 * bad design, and it does not prevent anyone from using the declaration---and experience has shown
 * that they will. If the method breaks the encapsulation of its class, then its internal
 * representation will be hard to change. Instead, use <a

   * or extract a variable, and put the suppression on that. However, a local variable typically
   * doesn't work: Because nullness analyses typically infer the nullness of local variables,
   * there's no way to assign a {@code @Nullable T} to a field {@code T foo;} and instruct the
   * analysis that that means "plain {@code T}" rather than the inferred type {@code @Nullable T}.

import java.util.Map.Entry;
import java.util.Set;
import javax.annotation.CheckForNull;

/**
 * A map-like data structure that wraps a backing map and caches values while iterating through
 * {@link #unmodifiableKeySet()}. By design, the cache is cleared when this structure is mutated. If
 * this structure is never mutated, it provides a thread-safe view of the backing map.
 *

   * or extract a variable, and put the suppression on that. However, a local variable typically
   * doesn't work: Because nullness analyses typically infer the nullness of local variables,
   * there's no way to assign a {@code @Nullable T} to a field {@code T foo;} and instruct the
   * analysis that that means "plain {@code T}" rather than the inferred type {@code @Nullable T}.

   * or extract a variable, and put the suppression on that. However, a local variable typically
   * doesn't work: Because nullness analyses typically infer the nullness of local variables,
   * there's no way to assign a {@code @Nullable T} to a field {@code T foo;} and instruct the
   * analysis that that means "plain {@code T}" rather than the inferred type {@code @Nullable T}.

  }

  /*
   * To avoid the need to call requireNonNull so much, we could consider more clever approaches,
   * such as:
   *
   * - Make checkOpen return the non-null `seq`. Then callers can assign that to a local variable or
   *   even back to `this.seq`. However, that may suggest that we're defending against concurrent
   *   mutation, which is not an actual risk because we use `synchronized`.

   * or the least double greater than or equal to the precise value of x.
   */
  abstract double roundToDoubleArbitrarily(X x);

  /** Returns the sign of x: either -1, 0, or 1. */
  abstract int sign(X x);

  /** Returns d's value as an X, rounded with the specified mode. */
  abstract X toX(double d, RoundingMode mode);

  /** Returns a - b, guaranteed that both arguments are nonnegative. */

   * {@link Collection#contains(Object)} (which does not generally throw if the object cannot be
   * present in the collection), and the desire to have this method's behavior be compatible with
   * {@code edges().contains(endpoints)}.
   *
   * @since 27.1
   */
  boolean hasEdgeConnecting(EndpointPair<N> endpoints);