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: chain.rb
    path of file: ./repos/newrelic-ruby-agent/lib/new_relic/agent/instrumentation/grape
    
    the code of the file until where you have to start completion: # This file is distributed under New Relic's license terms.
# See https://github.com/newrelic/newrelic-ruby-agent/blob/main/LICENS
    
      def self.instrument!
        Grape::Instrumentation.instrumented_class.class_eval do
          def call_with_new_relic(env)
            begin
              call_without_new_relic(env)
            ensure
              Grape::Instrumentation.capture_transaction(env, self)
            end
          end

          alias_method(:call_without_new_relic, :call)
          alias_method(:call, :call_with_new_relic)
        end