code: func (pool *TxPool) SetGasPrice(price *big.Int) {
  	pool.mu.Lock()
  	defer pool.mu.Unlock()
  
  	pool.gasPrice = price
  	for _, tx := range pool.priced.Cap(price, pool.locals) {
  		pool.removeTx(tx.Hash(), false)
  	}
  	log.Info("Transaction pool price threshold updated", "price", price)
  }
docs: // SetGasPrice updates the minimum price required by the transaction pool for a
  // new transaction, and drops all transactions below this threshold.