code: public Observable<Contacts> deleteCertificateContactsAsync(String vaultBaseUrl) {
          return deleteCertificateContactsWithServiceResponseAsync(vaultBaseUrl).map(new Func1<ServiceResponse<Contacts>, Contacts>() {
              @Override
              public Contacts call(ServiceResponse<Contacts> response) {
                  return response.body();
              }
          });
      }
docs: Deletes the certificate contacts for a specified key vault.
  Deletes the certificate contacts for a specified key vault certificate. This operation requires the certificates/managecontacts permission.
  
  @param vaultBaseUrl The vault name, for example https://myvault.vault.azure.net.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the Contacts object