# File lib/ec2/right_ec2_spot_instances.rb, line 66
    def describe_spot_price_history(options={})
      options = options.dup
      request_hash = {}
      request_hash['StartTime']          = AwsUtils::utc_iso8601(options[:start_time])     unless options[:start_time].blank?
      request_hash['EndTime']            = AwsUtils::utc_iso8601(options[:end_time])       unless options[:end_time].blank?
      request_hash['ProductDescription'] = options[:product_description]                   unless options[:product_description].blank?
      request_hash.merge!(amazonize_list('InstanceType', Array(options[:instance_types]))) unless options[:instance_types].blank?
      link = generate_request("DescribeSpotPriceHistory", request_hash)
      request_info(link, QEc2DescribeSpotPriceHistoryParser.new)
    rescue Exception
      on_exception
    end