You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: widget.rb
    path of file: ./repos/hexapdf/lib/hexapdf/type/annotations
    
    the code of the file until where you have to start completion: # -*- encoding: utf-8; frozen_string_literal: true -*-
#
#--
# This file is part of HexaPDF.
#
# HexaPDF - A Versatile PDF Creation and Manipulation Library For
    
        def form_field
          field = if key?(:Parent) &&
                      (tmp = document.wrap(self[:Parent], type: :XXAcroFormField)).terminal_field?
                    tmp
                  else
                    document.wrap(self, type: :XXAcroFormField)
                  end
          document.wrap(field, type: :XXAcroFormField, subtype: field[:FT])
        end