extractEntityFromRoute example

$contexts['layout_builder.entity'] = EntityContext::fromEntity($entity);
    return $contexts;
  }

  /** * {@inheritdoc} */
  public function deriveContextsFromRoute($value, $definition, $name, array $defaults) {
    $contexts = [];

    if ($entity = $this->extractEntityFromRoute($value, $defaults)) {
      $contexts['display'] = EntityContext::fromEntity($entity);
    }
    return $contexts;
  }

  /** * Extracts an entity from the route values. * * @param mixed $value * The raw value from the route. * @param array $defaults * The route defaults array. * * @return \Drupal\Core\Entity\EntityInterface|null * The entity for the route, or NULL if none exist. * * @see \Drupal\layout_builder\SectionStorageInterface::deriveContextsFromRoute() * @see \Drupal\Core\ParamConverter\ParamConverterInterface::convert() */

$key .= '.' . $entity->language()->getId();
    }
    return $key;
  }

  /** * {@inheritdoc} */
  public function deriveContextsFromRoute($value, $definition, $name, array $defaults) {
    $contexts = [];

    if ($entity = $this->extractEntityFromRoute($value, $defaults)) {
      $contexts['entity'] = EntityContext::fromEntity($entity);
      // @todo Expand to work for all view modes in       // https://www.drupal.org/node/2907413.       $view_mode = 'full';
      // Retrieve the actual view mode from the returned view display as the       // requested view mode may not exist and a fallback will be used.       $view_mode = LayoutBuilderEntityViewDisplay::collectRenderDisplay($entity, $view_mode)->getMode();
      $contexts['view_mode'] = new Context(new ContextDefinition('string'), $view_mode);
    }
    return $contexts;
  }