relationship = $relationship; $this->type = $type; $this->value = $value; } public function __toString() { // There is no $this->data here return md5(serialize($this)); } public function get_relationship() { if ($this->relationship !== null) { return $this->relationship; } else { return null; } } public function get_type() { if ($this->type !== null) { return $this->type; } else { return null; } } public function get_value() { if ($this->value !== null) { return $this->value; } else { return null; } } }