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: thread.rb
    path of file: ./repos/facets/lib/standard/facets
    
    the code of the file until where you have to start completion: # = Thread Related Extensions
#
# This a small colleciton of thread-related extensions.

require 'thread'

#require 'facets/binding/eval'
#require 'facets/kernel/__method__'

# This is the non-threaded form of #threaded_map_send.
require 'facets/enumerable/m
    
  def sandbox(rescueblock_or_default=nil) #:yield:
    Thread.start do
      $SAFE = 4
      yield
    end.value
  rescue SecurityError => e
    if !rescueblock_or_default.nil?
      if rescueblock_or_default.is_a? Proc
        rescueblock_or_default.call e
      else
        rescueblock_or_default
      end
    else
      raise e
    end