# File lib/oauth/signature.rb, line 11
    def self.build(request, options = {}, &block)
      request = OAuth::RequestProxy.proxy(request, options)
      klass = available_methods[
        (request.signature_method ||
        ((c = request.options[:consumer]) && c.options[:signature_method]) ||
        "").downcase]
      raise UnknownSignatureMethod, request.signature_method unless klass
      klass.new(request, options, &block)
    end