function decimals() external view returns (uint8)
function latestAnswer() external view returns (int256)
function latestTimestamp() external view returns (uint256)
function latestRound() external view returns (uint256)
function getAnswer(uint256 roundId) external view returns (int256)
function getTimestamp(uint256 roundId) external view returns (uint256)
event AnswerUpdated(int256 current, uint256 roundId, uint256 timestamp)
event NewRound(uint256 roundId, address startedBy)
