src/EventEmitterTrait.php
public function removeListeners(string $event = null) : self
    {
        if (null !== $event) {
            unset($this->listeners[$event]);
        } else {
            $this->listeners = [];
        }

        return $this;
    }
public function removeListeners(string $event = null) : self
    {
        if (null !== $event) {
            unset($this->listeners[$event]);
        } else {
            $this->listeners = [];
        }

        return $this;
    }
@param string $event

@return $this