# File lib/yadis/xri.rb, line 65
  def root_authority(xri)
    xri = xri[6..-1] if xri.index('xri://') == 0
    authority = xri.split('/', 2)[0]
    if authority[0].chr == '('
      root = authority[0...authority.index(')')+1]
    elsif XRI_AUTHORITIES.member?(authority[0].chr)
      root = authority[0].chr
    else
      root = authority.split(/[!*]/)[0]
    end
    
    make_xri(root)
  end