#include <FWCore/ParameterSet/interface/ParameterSetDescription.h>
Description: Used to describe the allowed values in a ParameterSet
Usage: <usage>
Implementation Details:
Note that there are some comments in the file ParameterDescriptionNode.h that might be useful for someone attempting to understand the implementation details. This class holds a container full of nodes. One node can represent a description of a single parameter or some logical restriction on the combinations of parameters allowed in a ParameterSet. Often these logical restrictions are implemented by the nodes themselves containing a tree structure of other nodes.