class Addressable::URI

def self.encode(uri, return_type=String)
  return nil if uri.nil?
  begin
    uri = uri.to_str
  rescue NoMethodError, TypeError
    raise TypeError, "Can't convert #{uri.class} into String."
  end if !uri.is_a? String
  if ![String, ::Addressable::URI].include?(return_type)
    raise TypeError,
      "Expected Class (String or Addressable::URI), " +
      "got #{return_type.inspect}"
  end
  uri_object = uri.kind_of?(self) ? uri : self.parse(uri)
  encoded_uri = Addressable::URI.new(
    :scheme => self.encode_component(uri_object.scheme,
      Addressable::URI::CharacterClasses::SCHEME),
    :authority => self.encode_component(uri_object.authority,
      Addressable::URI::CharacterClasses::AUTHORITY),
    :path => self.encode_component(uri_object.path,
      Addressable::URI::CharacterClasses::PATH),
    :query => self.encode_component(uri_object.query,
      Addressable::URI::CharacterClasses::QUERY),
    :fragment => self.encode_component(uri_object.fragment,
      Addressable::URI::CharacterClasses::FRAGMENT)
  )
  if return_type == String
    return encoded_uri.to_s
  elsif return_type == ::Addressable::URI
    return encoded_uri
  end
end