castSafeStrings example

  public function setData(array $data) {
    $data = $this->castSafeStrings($data);
    $this->validateKeys($data);
    $this->data = $data;
    return $this;
  }

  /** * Sets a value in this configuration object. * * @param string $key * Identifier to store value in configuration. * @param mixed $value * Value to associate with identifier. * * @return $this * The configuration object. * * @throws \Drupal\Core\Config\ConfigValueException * If $value is an array and any of its keys in any depth contains a dot. */