code: public static <T> Predicate<T> and(Predicate<T> first, Predicate<T> second) {
          dbc.precondition(first != null, "first predicate is null");
          dbc.precondition(second != null, "second predicate is null");
          return Logic.Unary.and(Iterations.iterable(first, second));
      }
docs: Creates a composite AND predicate from the given predicates.
  
  @param <T> the element type parameter
  @param first
  @param second
  @return the composite predicate