This identity is applicable if the hardware class is capable
of containing one or more removable physical entities,
possibly of different types. For example, each (empty or
full) slot in a chassis will be modeled as a container. Note
that all removable physical components should be modeled
within a container component, such as field-replaceable
modules, fans, or power supplies. Note that all known
containers should be modeled by the agent, including empty
containers.