message: Add Comments
  This commit fixes a review suggestion from thomas to add some clarifying
  comments for contractaddress and tokenaddress
  Ticket:
diff: @@ -147,6 +147,7 @@ export class TransactionBuilder extends BaseTransactionBuilder {
  if (transactionJson.to === undefined) {
  throw new BuildTransactionError('Undefined recipient address');
  }
  + // the address of the wallet contract that we are calling "flushForwarderTokens" on
  this._contractAddress = transactionJson.to;
  const { forwarderAddress, tokenAddress } = Utils.decodeFlushTokensData(transactionJson.data);
  this._forwarderAddress = forwarderAddress;
  @@ -503,7 +504,7 @@ export class TransactionBuilder extends BaseTransactionBuilder {
  }
  /**
  - * Set the token address to flush
  + * Set the address of the ERC20 token contract that we are flushing tokens for
  *
  * @param {string} address the contract address of the token to flush
  */
  