function cider.entity.isDoor(entity)
    local class = entity:GetClass();

    -- Check if the entity is a valid door class.
    if (class == "func_door" or class == "func_door_rotating" or class == "prop_door_rotating" or class == "prop_vehicle_prisoner_pod" or class == "prop_vehicle_jeep") then
        return true;
    else
        return false;
    end;
end;