public function column_headers( $columns ) {
		$columns = array(
			'cb'                    => '<input type="checkbox" />',
			'title'                 => esc_html__( 'Topics',    'bbpress' ),
			'bbp_topic_forum'       => esc_html__( 'Forum',     'bbpress' ),
			'bbp_topic_reply_count' => esc_html__( 'Replies',   'bbpress' ),
			'bbp_topic_voice_count' => esc_html__( 'Voices',    'bbpress' ),
			'bbp_topic_author'      => esc_html__( 'Author',    'bbpress' ),
			'bbp_topic_created'     => esc_html__( 'Created',   'bbpress' ),
			'bbp_topic_freshness'   => esc_html__( 'Last Post', 'bbpress' )
		);

		// Filter & return
		return (array) apply_filters( 'bbp_admin_topics_column_headers', $columns );
	}