def get_route_by_cidr(route_table, cidr):
    """Method to check if given CIDR already attached to route table.
    Args:
        RouteTable (obj): Route Table object.
        cidr (str): CIDR string to check in route table.
    Returns:
        Route: the route for this CIDR or None if not found
    """
    return dict((r.destination_cidr_block, r) for r in route_table.routes).get(cidr)