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: veteran.rb
    path of file: ./repos/vets-api/modules/va_notify/app/models/va_notify
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

module VANotify
  class Veteran
    class UnsupportedForm < StandardError; end
    class MPIError < StandardError; end
    class MPINameError < StandardError; end

 
    
    def lookup_first_name_by_icn
      mpi_profile = MPI::Service.new.find_profile_by_identifier(identifier: icn, identifier_type: MPI::Constants::ICN)
      raise MPIError unless mpi_profile.ok?

      first_name = mpi_profile.profile.given_names&.first
      raise MPINameError unless first_name

      first_name
    end