code: public void setTransactionAmount(com.google.api.ads.adwords.axis.v201809.rm.MoneyWithCurrency transactionAmount) {
          this.transactionAmount = transactionAmount;
      }
docs: Sets the transactionAmount value for this StoreSalesTransaction.
  
  @param transactionAmount   * Transaction amount. We support the ISO 4217 3-character currency
  code. For example: USD, EUR.
  <span class="constraint Required">This field is required
  and should not be {@code null}.</span>