def in_dir(dir, &block)
      original_dir = Dir.pwd
      begin
        Dir.chdir(dir)
        block.call
      ensure
        Dir.chdir(original_dir)
      end
    end
def in_dir(dir, &block)
      original_dir = Dir.pwd
      begin
        Dir.chdir(dir)
        block.call
      ensure
        Dir.chdir(original_dir)
      end
    end
Evaluate block after changing directory to specified directory