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: exceptions.rb
    path of file: ./repos/chef/lib/chef/chef_fs/file_system
    
    the code of the file until where you have to start completion: #
# Author:: Thom May (<thom@chef.io>)
# Copyright:: Copyright (c) Chef Software Inc.
# License:: Apache License, Ve
    
        def initialize(operation, entry, cause = nil, reason = nil)
          reason ||=
            case operation
            when :delete
              "cannot be deleted"
            when :write
              "cannot be updated"
            when :create_child
              "cannot have a child created under it"
            when :read
              "cannot be read"
            end