code: func (l *MockLedger) SendFrom(blockNum uint64) {
  	l.RLock()
  	defer l.RUnlock()
  
  	if blockNum >= uint64(len(l.blocks)) {
  		return
  	}
  
  	for _, block := range l.blocks[blockNum:] {
  		for _, p := range l.consumers {
  			p <- l.eventFactory(block, l.sourceURL)
  		}
  	}
  }
docs: // SendFrom sends block events to all registered consumers from the
  // given block number