channel.messages.fetchPins() does not return

for (let location of locations) {
            let channel = guild.channels.cache.get(location.id) as TextChannel;
            if (channel) {
                let pinned = await channel.messages.fetchPins();
                if (!pinned) {
                    str += '<#' + channel.id + '> has no pins.\n';
                } else {
                    if (pinned.size < pins) {
                        str += '<#' + channel.id + '> Pin Number: ' + pinned.size + '\n';
                    }
                }
            } 
        }