code: public static PredicateExpression all(Object... rhs) {
          PredicateExpression ex = new PredicateExpression( "$all", rhs);
          if (rhs.length == 1) {
              ex.single = true;
          }
          return ex;
      }
docs: Matches an array value if it contains all the elements of the argument array
  @param rhs The arguments
  @return PredicateExpression: $all rhs