code: public Observable<StorageAccountInner> createAsync(String resourceGroupName, String accountName, StorageAccountCreateParameters parameters) {
          return createWithServiceResponseAsync(resourceGroupName, accountName, parameters).map(new Func1<ServiceResponse<StorageAccountInner>, StorageAccountInner>() {
              @Override
              public StorageAccountInner call(ServiceResponse<StorageAccountInner> response) {
                  return response.body();
              }
          });
      }
docs: Asynchronously creates a new storage account with the specified parameters. If an account is already created and a subsequent create request is issued with different properties, the account properties will be updated. If an account is already created and a subsequent create or update request is issued with the exact same set of properties, the request will succeed.
  
  @param resourceGroupName The name of the resource group within the user's subscription. The name is case insensitive.
  @param accountName The name of the storage account within the specified resource group. Storage account names must be between 3 and 24 characters in length and use numbers and lower-case letters only.
  @param parameters The parameters to provide for the created account.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable for the request