checkState(count() > 1);
    return sumOfProductsOfDeltas / (count() - 1);
  }

  /**
   * Returns the <a href="http://mathworld.wolfram.com/CorrelationCoefficient.html">Pearson's or
   * product-moment correlation coefficient</a> of the values. The count must greater than one, and
   * the {@code x} and {@code y} values must both have non-zero population variance (i.e. {@code

    }
    return false;
  }

  // Prevent "missing hashCode" warning by explicitly forcing subclasses implement it
  @Override
  public abstract int hashCode();

  /*
   * The implementation neither produces nor consumes any non-null instance of type C, so
   * casting the type parameter is safe.
   */
  @SuppressWarnings("unchecked")
  static <C extends Comparable> Cut<C> belowAll() {
    return (Cut<C>) BelowAll.INSTANCE;

## Common Use Cases

### E-commerce Search

```java
// Product search suggestions
SuggestItem product = new SuggestItem(
    new String[]{"iPhone 15 Pro", "Apple iPhone 15 Pro"},
    new String[][]{{"iphone"}, {"apple", "phone"}},
    1.5f,                               // boost popular products
    new String[]{"electronics", "mobile"},
    new String[]{"customer"},
    SuggestItem.Kind.DOCUMENT

  }

  /**
   * Asserts that the given object is non-null, with a better failure message than {@link
   * TestCase#assertNull(String, Object)}.
   *
   * <p>The {@link TestCase} version (which is from JUnit 3) produces a failure message that does
   * not include the value of the object.
   *
   * @since 33.4.0
   */
  public static void assertNull(String message, Object object) {
    assertEquals(message, null, object);
  }

        axesSizeProduct[i] = Math.multiplyExact(axesSizeProduct[i + 1], axes.get(i).size());
      }
    } catch (ArithmeticException e) {
      throw new IllegalArgumentException(
          "Cartesian product too large; must have size at most Integer.MAX_VALUE");
    }
    this.axesSizeProduct = axesSizeProduct;
  }

  private int getAxisIndexForProductIndex(int index, int axis) {

    img: https://fastapi.tiangolo.com/img/sponsors/scalar.svg
  - url: https://www.propelauth.com/?utm_source=fastapi&utm_campaign=1223&utm_medium=mainbadge
    title: Auth, user management and more for your B2B product
    img: https://fastapi.tiangolo.com/img/sponsors/propelauth.png
  - url: https://zuplo.link/fastapi-gh
    title: 'Zuplo: Deploy, Secure, Document, and Monetize your FastAPI'

import org.apache.maven.api.model.PluginContainer;

/**
 * Represents the packaging of a Maven project.
 *
 * <p>The {@code Packaging} class defines the type of artifact that a Maven project produces during the build process.
 * The packaging type determines the structure of the project's output and how Maven will treat the resulting artifact.</p>
 *

    assertThrows(IllegalArgumentException.class, () -> Sets.newSetFromMap(map));
  }

  /** The 0-ary cartesian product is a single empty list. */
  public void testCartesianProduct_zeroary() {
    assertThat(cartesianProduct()).containsExactly(list());
  }

  /** A unary cartesian product is one list of size 1 for each element in the input set. */
  public void testCartesianProduct_unary() {

## Opinions { #opinions }

"_[...] I'm using **FastAPI** a ton these days. [...] I'm actually planning to use it for all of my team's **ML services at Microsoft**. Some of them are getting integrated into the core **Windows** product and some **Office** products._"

<div style="text-align: right; margin-right: 10%;">Kabir Khan - <strong>Microsoft</strong> <a href="https://github.com/fastapi/fastapi/pull/26" target="_blank"><small>(ref)</small></a></div>

---

                MapFeature.GENERAL_PURPOSE)
            /*
             * StandardDescendingMap uses lowerEntry(), and TreeMap.lowerEntry() deliberately
             * produces immutable entries.
             *
             * TODO(cpovirk): Consider making StandardDescendingMap return a ForwardingEntry that
             * supports setValue().
             */
            .suppressing(