code: func (api *PrivateMinerAPI) SetGasPrice(gasPrice hexutil.Big) bool {
  	api.e.lock.Lock()
  	api.e.gasPrice = (*big.Int)(&gasPrice)
  	api.e.lock.Unlock()
  
  	api.e.txPool.SetGasPrice((*big.Int)(&gasPrice))
  	return true
  }
docs: // SetGasPrice sets the minimum accepted gas price for the miner.