Selectable is an interface which represents an object (such as a socket
or file descriptor) which may be used with the SelectItem and SelectSet
classes.
This signal indicates that all stages specified in the
initial Sandstorm configuration, or created during the
init() method from a stage specified in the
initial configuration, have been initialized.
The ssLinkedList class is just that - a linked list abstraction that
supports very efficient insertion and deletion, as well as an
Enumeration interface.