contract OasisInterface {
      // function createAndBuyAllAmountPayEth(address factory, address otc, address buyToken, uint buyAmt) public payable returns (address proxy, uint wethAmt);
      function buyAllAmountPayEth(address otc, address buyToken, uint buyAmt, address wethToken) public payable returns (uint wethAmt);

}
function buyAllAmountPayEth(address otc, address buyToken, uint buyAmt, address wethToken) public payable returns (uint wethAmt);

// function createAndBuyAllAmountPayEth(address factory, address otc, address buyToken, uint buyAmt) public payable returns (address proxy, uint wethAmt);