code: public Observable<ServiceResponse<AccessUriInner>> beginGrantAccessWithServiceResponseAsync(String resourceGroupName, String diskName, GrantAccessData grantAccessData) {
          if (this.client.subscriptionId() == null) {
              throw new IllegalArgumentException("Parameter this.client.subscriptionId() is required and cannot be null.");
          }
          if (resourceGroupName == null) {
              throw new IllegalArgumentException("Parameter resourceGroupName is required and cannot be null.");
          }
          if (diskName == null) {
              throw new IllegalArgumentException("Parameter diskName is required and cannot be null.");
          }
          if (this.client.apiVersion() == null) {
              throw new IllegalArgumentException("Parameter this.client.apiVersion() is required and cannot be null.");
          }
          if (grantAccessData == null) {
              throw new IllegalArgumentException("Parameter grantAccessData is required and cannot be null.");
          }
          Validator.validate(grantAccessData);
          return service.beginGrantAccess(this.client.subscriptionId(), resourceGroupName, diskName, this.client.apiVersion(), grantAccessData, this.client.acceptLanguage(), this.client.userAgent())
              .flatMap(new Func1<Response<ResponseBody>, Observable<ServiceResponse<AccessUriInner>>>() {
                  @Override
                  public Observable<ServiceResponse<AccessUriInner>> call(Response<ResponseBody> response) {
                      try {
                          ServiceResponse<AccessUriInner> clientResponse = beginGrantAccessDelegate(response);
                          return Observable.just(clientResponse);
                      } catch (Throwable t) {
                          return Observable.error(t);
                      }
                  }
              });
      }
docs: Grants access to a disk.
  
  @param resourceGroupName The name of the resource group.
  @param diskName The name of the managed disk that is being created. The name can't be changed after the disk is created. Supported characters for the name are a-z, A-Z, 0-9 and _. The maximum name length is 80 characters.
  @param grantAccessData Access data object supplied in the body of the get disk access operation.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the AccessUriInner object