src/Models/BitrixModel.php
protected function fieldShouldNotBeSaved($field, $value, $selectedFields)
    {
        $blacklistedFields = [
            'ID',
            'IBLOCK_ID',
            'GROUPS',
        ];

        return (!empty($selectedFields) && !in_array($field, $selectedFields))
            || in_array($field, $blacklistedFields)
            || ($field[0] === '~')
            || (substr($field, 0, 9) === 'PROPERTY_')
            || (is_array($this->original) && array_key_exists($field, $this->original) && $this->original[$field] === $value);
    }
protected function fieldShouldNotBeSaved($field, $value, $selectedFields)
    {
        $blacklistedFields = [
            'ID',
            'IBLOCK_ID',
            'GROUPS',
        ];

        return (!empty($selectedFields) && !in_array($field, $selectedFields))
            || in_array($field, $blacklistedFields)
            || ($field[0] === '~')
            || (substr($field, 0, 9) === 'PROPERTY_')
            || (is_array($this->original) && array_key_exists($field, $this->original) && $this->original[$field] === $value);
    }
Determine whether the field should be stopped from passing to "update".

@param string $field
@param mixed  $value
@param array  $selectedFields

@return bool