src/SubConnection.js
function subscribe (channels) {
    channels.forEach(channel => {
      if (~_subscribedChannels.indexOf(channel)) return
      _subscribedChannels.push(channel)
      if (_socket) _socket.subscribe(channel)
    })
    return connection
  }
function subscribe (channels) {
    channels.forEach(channel => {
      if (~_subscribedChannels.indexOf(channel)) return
      _subscribedChannels.push(channel)
      if (_socket) _socket.subscribe(channel)
    })
    return connection
  }
function subscribe ( channels ) { channels . forEach ( channel => { if ( ~ _subscribedChannels . indexOf ( channel ) ) return _subscribedChannels . push ( channel ) if ( _socket ) _socket . subscribe ( channel ) } ) return connection }
subscribes the component to the passed channels
@param  {[string]} channels
@return {object} the subscribeConnection instance
subscribes the component to the passed channels