Returns `Accept` based on an array of accepts provided.

        :param accepts: List of headers.
        :return: Accept (e.g. application/json).

def select_header_accept(self, accepts):
        """
        Returns `Accept` based on an array of accepts provided.

        :param accepts: List of headers.
        :return: Accept (e.g. application/json).
        """
        if not accepts:
            return

        accepts = [x.lower() for x in accepts]

        if 'application/json' in accepts:
            return 'application/json'
        else:
            return ', '.join(accepts)