Error Warning Removed by adding one line of code

In the code of the class SiteOrigin_Widget_Field_Link
add the line in red to remove a warning, could you include this correction in your code for future updates ?

/**
* Class SiteOrigin_Widget_Field_Link
*/
class SiteOrigin_Widget_Field_Link extends SiteOrigin_Widget_Field_Text_Input_Base {

/**
* An array of post types to use in the query for posts when the ‘Select Content’ button is clicked.
*
* @access protected
* @var array
*/
protected $post_types;

protected function render_before_field( $value, $instance ) {
parent::render_before_field( $value, $instance );
if(!is_array($this->post_types)) $this->post_types=array();
?>

<input type="text" class="content-text-search"
data-post-types="post_types ) ) ?>”
placeholder=””/>

<?php
parent::render_after_field( $value, $instance );
}

protected function sanitize_field_input( $value, $instance ) {
$sanitized_value = trim( $value );
if ( preg_match( '/^post: *([0-9]+)/', $sanitized_value, $matches ) ) {
$sanitized_value = 'post: ' . $matches[1];
} else {
$sanitized_value = sow_esc_url_raw( $sanitized_value );
}

return $sanitized_value;
}

}