remix-project/remix-tests/examples/simple_storage.sol

pragma solidity ^0.5.0;
contract SimpleStorage {
  uint public storedData;

  constructor() public {
    storedData = 100;
  }

  function set(uint x) public {
    storedData = x;
  }

  function get() public view returns (uint retVal) {
    return storedData;
  }

}