steem.api.setSubscribeCallback(callback, clearFilter, function(err, result) {
  console.log(err, result);
});

steem.api.setPendingTransactionCallback(cb, function(err, result) {
  console.log(err, result);
});

steem.api.setBlockAppliedCallback(cb, function(err, result) {
  console.log(err, result);
});

steem.api.cancelAllSubscriptions(function(err, result) {
  console.log(err, result);
});