public ToStringHelper add(String name, double value) {
      return addHolder(name, String.valueOf(value));
    }
Adds a name/value pair to the formatted output in {@code name=value} format.

@since 18.0 (since 11.0 as {@code Objects.ToStringHelper.add()}).
fbcore/src/main/java/com/facebook/common/internal/Objects.java