def touch(option={})
      mode = option[:mode] || 0600
      path = create(option)
      path.open("w", mode)
      return path
    end
def touch(option={})
      mode = option[:mode] || 0600
      path = create(option)
      path.open("w", mode)
      return path
    end
Create a empty file.

 @param option [Hash]
 @option option [Integer] :mode
   mode for the file permission
 @option option [String] :basename
   prefix of filename
 @option option [Pathname] :basedir
   pathname of base directory