node.js:134
        throw e; // process.nextTick error, or 'error' event on first tick
        ^
Error: EPIPE, Broken pipe
    at Socket._writeImpl (net.js:159:14)
    at Socket._writeOut (net.js:444:25)
    at Socket.flush (net.js:523:24)
    at Socket.end (net.js:873:14)
    at Socket.closeSocket (/opt/services/webpush/support/webpush-engine/node_modules/ws/lib/WebSocket.js:508:20)
    at Socket.emit (events.js:61:17)
    at Socket._onReadable (net.js:652:51)
    at IOWatcher.onReadable (net.js:177:10)