>description</dt><dd class="cmt"><p>human-readable description of this backend. Optional</p></dd><dt class="param">metadata</dt><dd class="cmt"><p>arbitrary user-defined machine-readable data of this backend. Optional</p></dd><dt class="param">backends</dt><dd class="cmt"><p>the ids of the child backends in order</p></dd></dl></div></li></ol></div><div class="values members"><h3>Value Members</h3><ol><li class="indented0 " name="scala.AnyRef#!=" group="Ungrouped" fullComment="yes" data-isabs="false" visbl="