protected function validateProperties($properties)
	{
		foreach ($this->required as $required) {
			if (!array_key_exists($required, $properties)) {
				throw new \InvalidArgumentException("Required open graph property [$required] is not present.");
			}
		}
	}
protected function validateProperties($properties)
	{
		foreach ($this->required as $required) {
			if (!array_key_exists($required, $properties)) {
				throw new \InvalidArgumentException("Required open graph property [$required] is not present.");
			}
		}
	}
protected function validateProperties ( $ properties ) { foreach ( $ this -> required as $ required ) { if ( ! array_key_exists ( $ required , $ properties ) ) { throw new \ InvalidArgumentException ( "Required open graph property [$required] is not present." ) ; } } }
Validate to make sure the properties contain all required ones.

@param array $properties
Validate to make sure the properties contain all required ones .