src/AbstractMessage.php
final public function clear($fieldName)
    {
        $this->guardFrozenMessage();
        $field = static::schema()->getField($fieldName);
        unset($this->data[$fieldName]);
        $this->clearedFields[$fieldName] = true;
        $this->populateDefault($field);
        return $this;
    }
final public function clear($fieldName)
    {
        $this->guardFrozenMessage();
        $field = static::schema()->getField($fieldName);
        unset($this->data[$fieldName]);
        $this->clearedFields[$fieldName] = true;
        $this->populateDefault($field);
        return $this;
    }
{@inheritdoc}
@return static