Source

File: wp-includes/class-wp-term.php

public function __get( $key ) {
		switch ( $key ) {
			case 'data':
				$data    = new stdClass();
				$columns = array( 'term_id', 'name', 'slug', 'term_group', 'term_taxonomy_id', 'taxonomy', 'description', 'parent', 'count' );
				foreach ( $columns as $column ) {
					$data->{$column} = isset( $this->{$column} ) ? $this->{$column} : null;
				}

				return sanitize_term( $data, $data->taxonomy, 'raw' );
		}
	}