baseConfigurationDefaults example

  public function getConfiguration() {
    return $this->configuration;
  }

  /** * {@inheritdoc} */
  public function setConfiguration(array $configuration) {
    $this->configuration = NestedArray::mergeDeep(
      $this->baseConfigurationDefaults(),
      $this->defaultConfiguration(),
      $configuration
    );
  }

  /** * Returns generic default configuration for block plugins. * * @return array * An associative array with the default configuration. */