long total = 0;
        while (from.read(buf) != -1) {
          ((Buffer) buf).flip();
          to.append(buf);
          total += buf.remaining();
          ((Buffer) buf).clear();
        }
        return total;
      }
    },
    NEW {
      @Override
      long copy(Readable from, Appendable to) throws IOException {
        return CharStreams.copy(from, to);
      }
    };

        long total = 0;
        while (from.read(buf) != -1) {
          ((Buffer) buf).flip();
          to.append(buf);
          total += buf.remaining();
          ((Buffer) buf).clear();
        }
        return total;
      }
    },
    NEW {
      @Override
      long copy(Readable from, Appendable to) throws IOException {
        return CharStreams.copy(from, to);
      }
    };

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[22] *}

/// tip

All this might seem contrived. And it might not be very clear how is it useful yet.

These examples are intentionally simple, but show how it all works.

In the chapters about security, there are utility functions that are implemented in this same way.

    final Table<R, C, V> original;

    TransposeTable(Table<R, C, V> original) {
      this.original = checkNotNull(original);
    }

    @Override
    public void clear() {
      original.clear();
    }

    @Override
    public Map<C, V> column(@ParametricNullness R columnKey) {
      return original.row(columnKey);
    }

    @Override
    public Set<R> columnKeySet() {

    unfiltered.remove("three");
    assertEquals(ImmutableMap.of("two", 2, "four", 4), unfiltered);
    assertEquals(ImmutableMap.of("four", 4), filtered);

    unfiltered.clear();
    assertEquals(ImmutableMap.of(), unfiltered);
    assertEquals(ImmutableMap.of(), filtered);
  }

  public void testFilteredValuesIllegalPut() {
    Map<String, Integer> unfiltered = createUnfiltered();

        }
        t.join(timeoutMillis);
        return !t.isAlive();
    }

    /**
     * 管理している {@link TimeoutTask}をクリアします。
     */
    public synchronized void clear() {
        timeoutTaskList.clear();
    }

    /**
     * {@link TimeoutTarget}を追加します。
     *
     * @param timeoutTarget target
     * @param timeout timeout
     * @param permanent permanent

        If you need help with Gradle or have a usage question, please reach [our community](http://help.gradle.org/) instead of creating an issue.

        If you found a clear typo, please open a PR with a fix instead of opening an issue.

  - type: dropdown
    id: issue-type
    attributes:
      label: Issue type
      options:
        - Wrong or misleading information

      map = makePopulatedMap();
    } catch (UnsupportedOperationException e) {
      return;
    }

    if (supportsClear) {
      map.clear();
      assertTrue(map.isEmpty());
    } else {
      assertThrows(UnsupportedOperationException.class, () -> map.clear());
    }
    assertInvariants(map);
  }

  @J2ktIncompatible // https://youtrack.jetbrains.com/issue/KT-58242/ undefined behavior (crash)

     * either it got collected, or {@link #clear} was called, or it wasn't set in the first place).
     */
    @CheckForNull
    V get();

    /** Returns the entry which contains this {@link WeakValueReference}. */
    E getEntry();

    /** Unsets the referenced value. Subsequent calls to {@link #get} will return {@code null}. */
    void clear();

    /**

    requestedUris.add(uri)
    return proxies
  }

  fun assertRequests(vararg expectedUris: URI?) {
    assertThat(requestedUris).containsExactly(*expectedUris)
    requestedUris.clear()
  }

  override fun connectFailed(
    uri: URI,
    sa: SocketAddress,
    ioe: IOException,
  ) {
    val socketAddress = sa as InetSocketAddress