def redact(digest=:sha1)
      raise "Unknown Digest type: #{digest}" unless %i(sha1 md5).include?(digest)
      return self.to_s if self.local.redacted?
      r = %Q({#{send(digest)}})
      r += "@" + self.host.to_s if self.host.to_s && self.host.to_s > " "
      r
    end
def redact(digest=:sha1)
      raise "Unknown Digest type: #{digest}" unless %i(sha1 md5).include?(digest)
      return self.to_s if self.local.redacted?
      r = %Q({#{send(digest)}})
      r += "@" + self.host.to_s if self.host.to_s && self.host.to_s > " "
      r
    end
Returns the redacted form of the address
 This format is defined by this libaray, and may change as usage increases.
 Takes either :sha1 (default) or :md5 as the argument