public void add(double x, double y) {
    // We extend the recursive expression for the one-variable case at Art of Computer Programming
    // vol. 2, Knuth, 4.2.2, (16) to the two-variable case. We have two value series x_i and y_i.
    // We define the arithmetic means X_n = 1/n \sum_{i=1}^n x_i, and Y_n = 1/n \sum_{i=1}^n y_i.
    // We also define the sum of the products of the differences from the means

import org.jspecify.annotations.NullUnmarked;

/**
 * Basher test for {@link ConcurrentHashMultiset}: start a bunch of threads, have each of them do
 * operations at random. Each thread keeps track of the per-key deltas that it's directly
 * responsible for; after all threads have completed, we sum the per-key deltas and compare to the
 * existing multiset values.
 *
 * @author mike nonemacher
 */

@NullUnmarked

    tests, either. This causes it to fail to find AtomicLongMapTest.

    Our workaround is to tell GWT that util.concurrent and all other packages
    have prod supersource, even if they have none. GWT is happy to ignore us
    when we specify a nonexistent path.

    (I hope that this workaround does not cause its own problems in the future.)
-->
<super-source path="super"/>

        } catch (ThemeException e) {
            assertEquals(expectedMessage, e.getMessage());
            assertNull(e.getCause());
        } catch (Exception e) {
            fail("Should have caught ThemeException, but caught: " + e.getClass());
        }
    }

    public void test_throwAndCatchWithCause() {
        // Test throwing and catching exception with cause

   * file. For discussion, see AbstractFutureState.
   */

  // Lazily initialized the first time we see an exception; not released until all the input futures
  // have completed and we have processed them all.
  volatile @Nullable Set<Throwable> seenExceptionsField = null;

  volatile int remainingField;

  private static final AtomicHelper ATOMIC_HELPER;

        facetQueryView.init();

        Map<String, String> queryMap = facetQueryView.getQueryMap();

        // Should have original non-filetype queries
        assertEquals("field:value", queryMap.get("label2"));
        assertEquals("anotherfield:anothervalue", queryMap.get("label3"));

        // Should have filetype queries
        assertEquals("filetype:html", queryMap.get("label1"));

    // duplicated key. We will use this final Entry to overwrite earlier slots in the entries array
    // that have the same key. Then a second pass will remove all but the first of the slots that
    // have this Entry. The value in the map becomes false when this first entry has been copied, so
    // we know not to copy the remaining ones.

Blocking APIs may be inefficient because you hold a thread idle while waiting on the network. Threads are expensive because they have both a memory overhead and a context-switching overhead.

#### Framed protocols

package com.google.common.cache;

import com.google.common.annotations.GwtCompatible;

/**
 * An object that can receive a notification when an entry is removed from a cache. The removal
 * resulting in notification could have occurred to an entry being manually removed or replaced, or
 * due to eviction resulting from timed expiration, exceeding a maximum size, or garbage collection.
 *

   * @param sampleKey a key of the same type as that contained by {@code multimap}. {@code multimap}
   *     may or may not have {@code sampleKey} as a key.
   * @param sampleValue a key of the same type as that contained by {@code multimap}. {@code
   *     multimap} may or may not have {@code sampleValue} as a key.
   */
  public static <K extends @Nullable Object, V extends @Nullable Object>