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: java8_methods_spec.rb
    path of file: ./repos/jruby/spec/java_integration/interfaces
    
    the code of the file until where you have to start completion: require File.dirname(__FILE__) + "/../spec_helper"

describe "an interface" do

  before :all do
    require 'tmpdir'; @tmpdir = Dir.mktmpdir
    files = []

    src = <<-JA
    
  def javac_compile(files)
    compiler = javax.tools.ToolProvider.getSystemJavaCompiler
    fmanager = compiler.getStandardFileManager(nil, nil, nil)
    diagnostics = nil
    units = fmanager.getJavaFileObjectsFromStrings( files.map { |fname| fname.to_s } )
    compilation_task = compiler.getTask(nil, fmanager, diagnostics, nil, nil, units)
    compilation_task.call # returns boolean
  end