code: function(cb){
  				deposit.getDepositAddressBySupernodeAddress(conn, objUnit.authors[0].address, function (err,depositAddress){
  					if(err)
  						 return cb(err + " can not send pow unit");
  					if(payload.deposit != depositAddress)
  						return cb("pow unit deposit address is invalid expeected :" + depositAddress +" Actual :" + payload.deposit);
  					deposit.getBalanceOfDepositContract(conn, depositAddress,objUnit.round_index,  function (err,balance){
  						if(err)
  							return cb(err);
  						depositBalance = balance;
  						cb();
  					   }); 
  				});
  			}
docs: check deposit address is valid and balance