code: @Override
    public void removeAuthorizedClient(String clientRegistrationId, String principalName) {
      Assert.hasText(clientRegistrationId, "clientRegistrationId cannot be empty");
      Assert.hasText(principalName, "principalName cannot be empty");
      ClientRegistration registration =
          this.clientRegistrationRepository.findByRegistrationId(clientRegistrationId);
      if (registration != null) {
        this.authorizedClients.remove(this.getIdentifier(registration, principalName));
      }
    }
docs: Copy of {@link InMemoryOAuth2AuthorizedClientService#removeAuthorizedClient(String, String)}