if (count == 1) {
      return 0.0;
    }
    return ensureNonNegative(sumOfSquaresOfDeltas) / count();
  }

  /**
   * Returns the <a
   * href="http://en.wikipedia.org/wiki/Standard_deviation#Definition_of_population_values">
   * population standard deviation</a> of the values. The count must be non-zero.
   *
   * <p>This is guaranteed to return zero if the dataset contains only exactly one finite value. It

public class TestmailPostcard extends LaTypicalPostcard {

    // ===================================================================================
    //                                                                          Definition
    //                                                                          ==========
    public static final String PATH = "testmail.dfmail";

    /**
     * Sets default values in the specified model that for technical reasons cannot be set directly in the Modello
     * definition.
     *
     * @param model The model in which to set the default values, must not be {@code null}.
     * @param request The model building request that holds further settings, must not be {@code null}.

   * This is not the same definition used by other Java APIs. (See a <a
   * href="https://goo.gl/Y6SLWx">comparison of several definitions of "whitespace"</a>.)
   *
   * <p>All Unicode White_Space characters are on the BMP and thus supported by this API.
   *
   * <p><b>Note:</b> as the Unicode definition evolves, we will modify this matcher to keep it up to
   * date.
   *

# WebSockets

Bei der Definition von WebSockets deklarieren Sie normalerweise einen Parameter vom Typ `WebSocket` und können damit Daten vom Client lesen und an ihn senden. Er wird direkt von Starlette bereitgestellt, Sie können ihn aber von `fastapi` importieren:

```python
from fastapi import WebSocket
```

!!! tip "Tipp"

import java.util.*;

import org.apache.maven.api.annotations.Experimental;
import org.apache.maven.api.annotations.Immutable;
import org.apache.maven.api.model.Plugin;

/**
 * Lifecycle definition
 *
 * @since 4.0.0
 */
@Experimental
@Immutable
public interface Lifecycle extends ExtensibleEnum {

    String CLEAN = "clean";

    String DEFAULT = "default";

    String SITE = "site";

      "Legal Entity" shall mean the union of the acting entity and all
      other entities that control, are controlled by, or are under common
      control with that entity. For the purposes of this definition,
      "control" means (i) the power, direct or indirect, to cause the
      direction or management of such entity, whether by contract or
      otherwise, or (ii) ownership of fifty percent (50%) or more of the

 */
public class BsGroup extends EsAbstractEntity {

    // ===================================================================================
    //                                                                          Definition
    //                                                                          ==========
    private static final long serialVersionUID = 1L;

See [Gradle runtimes](runtimes.md) for a list of these runtimes and more details.

## Build state model

As Gradle executes, it acts on various pieces of the build definition, such as each project in the build.
Gradle tracks the state of each piece and transitions each piece through its lifecycle as the build runs.

public class BsCrawlingInfoParam extends EsAbstractEntity {

    // ===================================================================================
    //                                                                          Definition
    //                                                                          ==========
    private static final long serialVersionUID = 1L;