code: public <T> MutateInBuilder arrayAddUnique(String path, T value, SubdocOptionsBuilder optionsBuilder) {
          asyncBuilder.arrayAddUnique(path, value, optionsBuilder);
          return this;
      }
docs: Insert a value in an existing array only if the value
  isn't already contained in the array (by way of string comparison).
  
  @param path the path to mutate in the JSON.
  @param value the value to insert.
  @param optionsBuilder {@link SubdocOptionsBuilder}