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<?php

if ( ! function_exists( 'yith_pos_customization_barcode_field' ) ) {
 add_filter( 'yith_pos_barcode_custom_field', 'yith_pos_customization_barcode_field' );

 function yith_pos_customization_barcode_field() {
  return "your_barcode_custom_field";
 }
}