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: control_type.rb
    path of file: ./repos/sequencescape/app/sequencescape_excel/sequencescape_excel/specialised_field
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

module SequencescapeExcel
  module SpecialisedField
    ##
    # Sets both control and contr
    
      def update(_attributes = {})
        return unless valid?

        if value.present?
          sample.control = true
          sample.control_type = value
        else
          sample.control = false
          sample.control_type = nil
        end