private void waitForPendingTransactionCounts(final TestNodeList nodes, final int expected) {
    Awaitility.await()
        .atMost(30, TimeUnit.SECONDS)
        .untilAsserted(
            () -> nodes.assertPendingTransactionCounts(expected, expected, expected, expected));
  }
Simulate a 4-node cluster. Send at least 1 Tx to each node, and multiple Tx to at least one
node. Verify that all nodes get the correct number of pending transactions.
ethereum/eth/src/test/java/org/hyperledger/besu/ethereum/eth/transactions/TransactionPoolPropagationTest.java