code: public Metadata add(String path, List<String> values) {
          JsonArray arr = new JsonArray();
          for (String value : values) {
              arr.add(value);
          }
          this.values.add(this.pathToProperty(path), arr);
          this.addOp("add", path, arr);
          return this;
      }
docs: Adds a new metadata value of array type.
  @param path the path to the field.
  @param values the collection of values.
  @return the metadata object for chaining.