private static boolean nonceGap(
      final TransactionEvaluationContext evaluationContext, final Long skippedNonce) {
    return skippedNonce != null && evaluationContext.getTransaction().getNonce() > skippedNonce;
  }
Check if this pending tx belongs to a sender with a previous pending tx not selected, in which
case we can safely skip the evaluation due to the nonce gap

@param evaluationContext The current selection session data.
@return SENDER_WITH_PREVIOUS_TX_NOT_SELECTED if there is a nonce gas for this sender
ethereum/blockcreation/src/main/java/org/hyperledger/besu/ethereum/blockcreation/txselection/selectors/SkipSenderTransactionSelector.java