getAllTransactionsForWallet(address) {
    const txs = [];

    for (const block of this.chain) {
      for (const tx of block.transactions) {
        if (tx.fromAddress === address || tx.toAddress === address) {
          txs.push(tx);
        }
      }
    }

    debug('get transactions for wallet count: %s', txs.length);
    return txs;
  }
Returns a list of all transactions that happened
to and from the given wallet address.

@param  {string} address
@return {Transaction[]}