If guess is correct, 2 cfx is returned and a new random number is generated and stored as meaningful variable.
If guess is not correct, 1 wei is returned and a new random number is generated and stored as non-meaningful variable.
Contract is Ownable really for educational and illustrative reasons. getNumber() and setRange() are not needed in a pure sense.
https://testnet.confluxscan.io/address/cfxtest:acc3sg8ffunb07cnrmt0xcwnx41wj5bhx2rga5w9rm