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: user.rb
    path of file: ./repos/airbrake/lib/airbrake/rack
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

module Airbrake
  module Rack
    # Represents an authenticated user, which can be converted to Airbrake's
    # payload f
    
      def as_json
        user = {}

        user[:id] = try_to_get(:id)
        user[:name] = full_name
        user[:username] = try_to_get(:username)
        user[:email] = try_to_get(:email)

        user = user.delete_if { |_key, val| val.nil? }
        user.empty? ? user : { user: user }
      end