@staticmethod
def _event_headers(flask_request, port):
    """
        Constructs an APIGW equivalent headers dictionary

        Parameters
        ----------
        flask_request request
            Request from Flask
        int port
            Forwarded Port
        cors_headers dict
            Dict of the Cors properties

        Returns dict (str: str), dict (str: list of str)
        -------
            Returns a dictionary of key to list of strings

        """
    headers_dict = {}
    multi_value_headers_dict = {}
    for header_key in flask_request.headers.keys():
        headers_dict[header_key] = flask_request.headers.get(header_key)
        multi_value_headers_dict[header_key] = flask_request.headers.getlist(
            header_key)
    headers_dict['X-Forwarded-Proto'] = flask_request.scheme
    multi_value_headers_dict['X-Forwarded-Proto'] = [flask_request.scheme]
    headers_dict['X-Forwarded-Port'] = str(port)
    multi_value_headers_dict['X-Forwarded-Port'] = [str(port)]
    return headers_dict, multi_value_headers_dict
