/**
 * A mutable object which accumulates paired double values (e.g. points on a plane) and tracks some
 * basic statistics over all the values added so far. This class is not thread safe.
 *
 * @author Pete Gillin
 * @since 20.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public final class PairedStatsAccumulator {

import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import junit.framework.TestCase;

/**
 * Tests for {@link PairedStats}. This tests instances created by {@link
 * PairedStatsAccumulator#snapshot}.
 *
 * @author Pete Gillin
 */
public class PairedStatsTest extends TestCase {

  public void testCount() {
    assertThat(EMPTY_PAIRED_STATS.count()).isEqualTo(0);
    assertThat(ONE_VALUE_PAIRED_STATS.count()).isEqualTo(1);

 * quantiles. All algorithms modify the dataset they are given (the cost of a copy to avoid this
 * will be constant across algorithms).
 *
 * @author Pete Gillin
 * @since 20.0
 */
enum QuantilesAlgorithm {

  /**
   * Sorts the dataset, and picks values from it. When computing multiple quantiles, we sort once
   * and pick multiple values.
   */
  SORTING {

/**
 * An immutable value object capturing some basic statistics about a collection of paired double
 * values (e.g. points on a plane). Build instances with {@link PairedStatsAccumulator#snapshot}.
 *
 * @author Pete Gillin
 * @since 20.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public final class PairedStats implements Serializable {

  private final Stats xStats;

 * {@link PairedStatsAccumulator#snapshot} method which returns {@link PairedStats} instances, see
 * {@link PairedStatsTest}.
 *
 * @author Pete Gillin
 */
public class PairedStatsAccumulatorTest extends TestCase {

  private PairedStatsAccumulator emptyAccumulator;
  private PairedStatsAccumulator emptyAccumulatorByAddAllEmptyPairedStats;

			}
			relationships.Relations[relation.Name] = relation
		}
	}
}

// User has many Toys, its `Polymorphic` is `Owner`, Pet has one Toy, its `Polymorphic` is `Owner`
//
//	type User struct {
//	  Toys []Toy `gorm:"polymorphic:Owner;"`
//	}
//	type Pet struct {
//	  Toy Toy `gorm:"polymorphic:Owner;"`
//	}
//	type Toy struct {
//	  OwnerID   int
//	  OwnerType string
//	}

**FastAPI**可与任何数据库在任何样式的库中一起与 数据库进行通信。

一种常见的模式是使用“ORM”：对象关系映射。

ORM 具有在代码和数据库表（“*关系型”）中的**对象**之间转换（“*映射*”）的工具。

使用 ORM，您通常会在 SQL 数据库中创建一个代表映射的类，该类的每个属性代表一个列，具有名称和类型。

例如，一个类`Pet`可以表示一个 SQL 表`pets`。

该类的每个*实例对象都代表数据库中的一行数据。*

又例如，一个对象`orion_cat`（`Pet`的一个实例）可以有一个属性`orion_cat.type`, 对标数据库中的`type`列。并且该属性的值可以是其它，例如`"cat"`。

这些 ORM 还具有在表或实体之间建立关系的工具（比如创建多表关系）。

这样，您还可以拥有一个属性`orion_cat.owner`，它包含该宠物所有者的数据，这些数据取自另外一个表。

/**
 * A mutable object which accumulates paired double values (e.g. points on a plane) and tracks some
 * basic statistics over all the values added so far. This class is not thread safe.
 *
 * @author Pete Gillin
 * @since 20.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public final class PairedStatsAccumulator {

 * {@link PairedStatsAccumulator#snapshot} method which returns {@link PairedStats} instances, see
 * {@link PairedStatsTest}.
 *
 * @author Pete Gillin
 */
public class PairedStatsAccumulatorTest extends TestCase {

  private PairedStatsAccumulator emptyAccumulator;
  private PairedStatsAccumulator emptyAccumulatorByAddAllEmptyPairedStats;

import java.util.List;
import java.util.Random;
import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tests for {@link Quantiles}.
 *
 * @author Pete Gillin
 */
public class QuantilesTest extends TestCase {

  /*
   * Since Quantiles provides a fluent-style API, each test covers a chain of methods resulting in