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: graphics_state.rb
    path of file: ./repos/hexapdf/lib/hexapdf/content
    
    the code of the file until where you have to start completion: # -*- encoding: utf-8; frozen_string_literal: true -*-
#
#--
# This file is part of Hex
    
      def self.normalize(style)
        case style
        when :butt, 0 then BUTT_CAP
        when :round, 1 then ROUND_CAP
        when :projecting_square, 2 then PROJECTING_SQUARE_CAP
        else
          raise ArgumentError, "Unknown line cap style: #{style}"
        end