Set a callback for worker warnings

public GearmanClient::setWarningCallback(callable $callback): bool

Sets a function to be called when a worker sends a warning. The callback should accept a single argument, a GearmanTask object.

Returns true on success or false on failure.

GearmanClient::setDataCallback() - Callback function when there is a data packet for a task
GearmanClient::setCompleteCallback() - Set a function to be called on task completion
GearmanClient::setCreatedCallback() - Set a callback for when a task is queued
GearmanClient::setExceptionCallback() - Set a callback for worker exceptions
GearmanClient::setFailCallback() - Set callback for job failure
GearmanClient::setStatusCallback() - Set a callback for collecting task status
GearmanClient::setWorkloadCallback() - Set a callback for accepting incremental data updates

GearmanClient::setWarningCallback