TestDataConverter.php

<?php

namespace Drupal\rdf_test;


/**
 * Contains methods for test data conversions.
 */
class TestDataConverter {
    
    /**
     * Converts data into a string for placement into a content attribute.
     *
     * @param array $data
     *   The data to be altered and placed in the content attribute.
     *
     * @return string
     *   Returns the data.
     */
    public static function convertFoo($data) {
        return 'foo' . $data['value'];
    }

}