code: function Blockchain (connector, opts) {
    var self = this
    EventEmitter.call(self)
  
    opts = _.extend({
      networkName: 'livenet',
      txCacheSize: 100
    }, opts)
  
    self.connector = connector
    self.networkName = opts.networkName
    self.latest = {hash: util.zfill('', 64), height: -1}
    self._txCache = LRU({max: opts.txCacheSize, allowSlate: true})
  
    self._isSyncing = false
    self.on('syncStart', function () { self._isSyncing = true })
    self.on('syncStop', function () { self._isSyncing = false })
  }
docs: @event Blockchain#touchAddress
  @param {string} address
   
  @class Blockchain
  @extends events.EventEmitter
  
  @param {Connector} connector
  @param {Object} [opts]
  @param {string} [opts.networkName=livenet]
  @param {number} [opts.txCacheSize=100]