code: public Currency getCurrency(String name) {
          Currency result;
          if (!currencyList.containsKey(name)) {
              result = Common.getInstance().getStorageHandler().getStorageEngine().getCurrency(name);
              if (result != null) {
                  currencyList.put(result.getName(), result);
              }
          } else {
              result = currencyList.get(name);
          }
          return result;
      }
docs: Get a currency
  
  @param name The name of the currency
  @return A currency instance if the currency is found else null