@SuppressWarnings("unchecked")
  public UsingRuleBuilder<T, U> using(String... factNames) {
    Rule<T, U> rule = _name.map(name -> (Rule<T, U>)new AuditableRule<T, U>(newRule(), name)).orElse(newRule());
    if (rule == null) {
      throw new IllegalStateException("No Rule is instantiated; An invalid Rule class may have been provided");
    }
    return new UsingRuleBuilder<T, U>(rule, factNames);
  }
@ SuppressWarnings ( "unchecked" ) public UsingRuleBuilder < T , U > using ( String ... factNames ) { Rule < T , U > rule = _name . map ( name -> ( Rule < T , U > ) new AuditableRule < T , U > ( newRule ( ) , name ) ) . orElse ( newRule ( ) ) ; if ( rule == null ) { throw new IllegalStateException ( "No Rule is instantiated; An invalid Rule class may have been provided" ) ; } return new UsingRuleBuilder < T , U > ( rule , factNames ) ; }
Adds a using constraint in the Rule that restricts the facts supplied to the subsequent 'then' action.
@param factNames the fact names to be supplied to the subsequent 'then' action
@return          a builder the allows for the Rule to be built following the 'using' statement