1  pragma solidity >=0.6.0;
 2  
 3  interface UnderlyingFeed {
 4  
 5      function symbol() external view returns (string memory);
 6  
 7      function getUnderlyingAddr() external view returns (address);
 8  
 9      function getPrivledgedPublisherKeeper() external view returns (address);
10  
11      function getUnderlyingAggAddr() external view returns (address);
12  
13      function getLatestPrice() external view returns (uint timestamp, int price);
14  
15      function getPrice(uint position) external view returns (uint timestamp, int price);
16  
17      function getDailyVolatility(uint timespan) external view returns (uint vol);
18  
19      function getDailyVolatilityCached(uint timespan) external view returns (uint vol, bool cached);
20  
21      function calcLowerVolatility(uint vol) external view returns (uint lowerVol);
22  
23      function calcUpperVolatility(uint vol) external view returns (uint upperVol);
24  
25      function prefetchSample() external;
26  
27      function prefetchDailyPrice(uint roundId) external;
28  
29      function prefetchDailyVolatility(uint timespan) external;
30  }