Wrapper for a
Layer to allow it to be dynamically reloaded.
This can be used in cases where a subset of
should be dynamically reconfigured, such as when filtering directives may
change at runtime. Note that this layer introduces a (relatively small)
amount of overhead, and should thus obly be used as needed.
Indicates that an error occurred when reloading a layer.
Allows reloading the state of an associated