contracts/smart-contract-wallet/paymasters/verifying/singleton/VerifyingSingletonPaymaster.sol:
  64      */
  65:     function setSigner( address _newVerifyingSigner) external onlyOwner{
  66:         require(_newVerifyingSigner != address(0), "VerifyingPaymaster: new signer can not be zero address");
  67:         verifyingSigner = _newVerifyingSigner;
  68:     }
