def api_headers(self, api_key: str):
        """API Headers needed to make calls to the REST API.

        Args:
            api_key: The key used for authenticating against the IonQ API.

        Returns:
            dict[str, str]: A dict of :class:`requests.Request` headers.
        """
        return {
            'Authorization': f'apiKey {api_key}',
            'Content-Type': 'application/json',
            'User-Agent': self._user_agent(),
        }
API Headers needed to make calls to the REST API.

        Args:
            api_key: The key used for authenticating against the IonQ API.

        Returns:
            dict[str, str]: A dict of :class:`requests.Request` headers.
        
cirq-ionq/cirq_ionq/ionq_client.py