code: func (b *SimulatedBackend) Commit() {
  	b.mu.Lock()
  	defer b.mu.Unlock()
  
  	if _, err := b.blockchain.InsertChain([]*types.Block{b.pendingBlock}); err != nil {
  		panic(err) // This cannot happen unless the simulator is wrong, fail in that case
  	}
  	b.rollback()
  }
docs: // Commit imports all the pending transactions as a single block and starts a
  // fresh new state.