code: public Observable<Contacts> getCertificateContactsAsync(String vaultBaseUrl) {
          return getCertificateContactsWithServiceResponseAsync(vaultBaseUrl).map(new Func1<ServiceResponse<Contacts>, Contacts>() {
              @Override
              public Contacts call(ServiceResponse<Contacts> response) {
                  return response.body();
              }
          });
      }
docs: Lists the certificate contacts for a specified key vault.
  The GetCertificateContacts operation returns the set of certificate contact resources in the specified key vault. 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