src/AbstractMessage.php
final public function isInList($fieldName, $value)
    {
        if (empty($this->data[$fieldName]) || !is_array($this->data[$fieldName])) {
            return false;
        }

        return in_array($value, $this->data[$fieldName]);
    }
final public function isInList($fieldName, $value)
    {
        if (empty($this->data[$fieldName]) || !is_array($this->data[$fieldName])) {
            return false;
        }

        return in_array($value, $this->data[$fieldName]);
    }
{@inheritdoc}