docs: public Future<AuthenticationResult> acquireToken(final String resource,
              final ClientCredential credential,
              final AuthenticationCallback callback) {
          this.validateInput(resource, credential, true);
          final ClientAuthentication clientAuth = new ClientSecretPost(
                  new ClientID(credential.getClientId()), new Secret(
                          credential.getClientSecret()));
          final AdalOAuthAuthorizationGrant authGrant = new AdalOAuthAuthorizationGrant(
                  new ClientCredentialsGrant(), resource);
          return this.acquireToken(authGrant, clientAuth, callback);
      }