public function do_items( $handles = false, $group = false ) {
		/*
		 * If nothing is passed, print the queue. If a string is passed,
		 * print that item. If an array is passed, print those items.
		 */
		$handles = false === $handles ? $this->queue : (array) $handles;
		$this->all_deps( $handles );

		foreach ( $this->to_do as $key => $handle ) {
			if ( ! in_array( $handle, $this->done, true ) && isset( $this->registered[ $handle ] ) ) {
				/*
				 * Attempt to process the item. If successful,
				 * add the handle to the done array.
				 *
				 * Unset the item from the to_do array.
				 */
				if ( $this->do_item( $handle, $group ) ) {
					$this->done[] = $handle;
				}

				unset( $this->to_do[ $key ] );
			}
		}

		return $this->done;
	}