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: cookies_config.rb
    path of file: ./repos/secure_headers/lib/secure_headers/utils
    
    the code of the file until where you have to start completion: # frozen_string_literal: true
module SecureHeaders
  class CookiesConfig

    attr_reader :config

    def initialize(config)
      @config = config
    end

    def validate!
      return if config.nil? || config == SecureHead
    
    def validate_samesite_hash_config!
      # validate Hash-based samesite configuration
      if is_hash?(config[:samesite][:lax])
        validate_exclusive_use_of_hash_constraints!(config[:samesite][:lax], "samesite lax")

        if is_hash?(config[:samesite][:strict])
          validate_exclusive_use_of_hash_constraints!(config[:samesite][:strict], "samesite strict")
          validate_exclusive_use_of_samesite_enforcement!(:only)
          validate_exclusive_use_of_samesite_enforcement!(:except)
        end