public function setValue($value)
	{
		if ( ! is_string($value) && ! is_int($value))
		{
			throw new \InvalidArgumentException('A RadioGroup value must be a string or int');
		}

		$this->value = $value;

		// Work out which of our children need to be selected
		foreach ($this->getContents() as $item)
		{
			if ($item->getValue() == $value)
			{
				$item->setChecked(true);
			}
			else
			{
				$item->setChecked(false);
			}
		}

		return $this;
	}