code: public Observable<VaultAccessPolicyParametersInner> updateAccessPolicyAsync(String resourceGroupName, String vaultName, AccessPolicyUpdateKind operationKind, VaultAccessPolicyProperties properties) {
          return updateAccessPolicyWithServiceResponseAsync(resourceGroupName, vaultName, operationKind, properties).map(new Func1<ServiceResponse<VaultAccessPolicyParametersInner>, VaultAccessPolicyParametersInner>() {
              @Override
              public VaultAccessPolicyParametersInner call(ServiceResponse<VaultAccessPolicyParametersInner> response) {
                  return response.body();
              }
          });
      }
docs: Update access policies in a key vault in the specified subscription.
  
  @param resourceGroupName The name of the Resource Group to which the vault belongs.
  @param vaultName Name of the vault
  @param operationKind Name of the operation. Possible values include: 'add', 'replace', 'remove'
  @param properties Properties of the access policy
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the VaultAccessPolicyParametersInner object