The request parameter "nodeOperation" must equal 0 for an expand/collapse operation, 1 for a check/uncheck
operation, 2 for a context menu operation, or an integer other than -1, 0, 1 or 2 for a custom operation.
This class is used to define the validation rules to be enforced on a Task parameter which is numeric (byte, short,
int, long, float, double, and corresponding Java wrapper classes).