def approve_paypal_payment_url(opts = {})
      if opts.is_a?(Symbol) || opts.is_a?(String)
        warn "[DEPRECATION] use approve_paypal_payment_url(:type => #{opts})"
        opts = {:type => opts}
      end
      return nil if self['payKey'].nil?

      if ['mini', 'light'].include?(opts[:type].to_s)
        "#{@paypal_base_url}/webapps/adaptivepayment/flow/pay?expType=#{opts[:type]}&paykey=#{self['payKey']}"
      else
        base = @paypal_base_url
        base = base + "/#{opts[:country]}" if opts[:country]
        "#{base}/webscr?cmd=_ap-payment&paykey=#{self['payKey']}"
      end
    end
def approve_paypal_payment_url(opts = {})
      if opts.is_a?(Symbol) || opts.is_a?(String)
        warn "[DEPRECATION] use approve_paypal_payment_url(:type => #{opts})"
        opts = {:type => opts}
      end
      return nil if self['payKey'].nil?

      if ['mini', 'light'].include?(opts[:type].to_s)
        "#{@paypal_base_url}/webapps/adaptivepayment/flow/pay?expType=#{opts[:type]}&paykey=#{self['payKey']}"
      else
        base = @paypal_base_url
        base = base + "/#{opts[:country]}" if opts[:country]
        "#{base}/webscr?cmd=_ap-payment&paykey=#{self['payKey']}"
      end
    end
URL to redirect to in order for the user to approve the payment

 options:
 * country: default country code for the user
 * type: mini / light