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: string_block_editor.rb
    path of file: ./repos/vagrant/lib/vagrant/util
    
    the code of the file until where you have to start completion: # Copyright (c) HashiCorp, Inc.
# SPDX-License-Identifier: BUSL-1.1

module Vagrant
  module Util
    # This class modifies str
    
      def insert(key, value)
        # Insert the new block into the value
        new_block = <<BLOCK
# VAGRANT-BEGIN: #{key}
#{value.strip}
# VAGRANT-END: #{key}
BLOCK

        @value << new_block
      end