type = new NullAttributeType(); $this->value = new NullAttributeValue(); } /** * Deep clone the attribute element * * @return self * * @since 1.0.0 */ public function deepClone() : self { $clone = clone $this; $clone->value = clone $this->value; return $clone; } /** * {@inheritdoc} */ public function toArray() : array { return [ 'id' => $this->id, 'ref' => $this->ref, 'type' => $this->type, 'value' => $this->value, ]; } /** * {@inheritdoc} */ public function jsonSerialize() : mixed { return $this->toArray(); } }