# File lib/git/lib.rb, line 593
    def commit_tree(tree, opts = {})
      opts[:message] ||= "commit tree #{tree}"
      t = Tempfile.new('commit-message')
      t.write(opts[:message])
      t.close
      
      arr_opts = []
      arr_opts << tree
      arr_opts << '-p' << opts[:parent] if opts[:parent]
      arr_opts += [opts[:parents]].map { |p| ['-p', p] }.flatten if opts[:parents]
      command('commit-tree', arr_opts, true, "< #{escape t.path}")
    end