private String parseScore(final String line) {
      int i = 0;
      final var sbScore = new StringBuilder();
      while ("1234567890-".indexOf(line.charAt(i)) >= 0) {
        sbScore.append(line.charAt(i++));
      }
      return sbScore.toString();
    }
Maintains the set of pending transactions received from JSON-RPC or other nodes. Transactions are
removed automatically when they are included in a block on the canonical chain and re-added if a
re-org removes them from the canonical chain again.

<p>This class is safe for use across multiple threads.
ethereum/eth/src/main/java/org/hyperledger/besu/ethereum/eth/transactions/TransactionPool.java