docs: static Policy setIamPolicySource(SourceName sourceName, String userEmail) {
      try (SecurityCenterClient client = SecurityCenterClient.create()) {
        // userEmail = "someuser@domain.com"
        // Set up IAM Policy for the user userMail to use the role findingsEditor.
        // The user must be a valid google account.
        Policy oldPolicy = client.getIamPolicy(sourceName.toString());
        Binding bindings =
            Binding.newBuilder()
                .setRole("roles/securitycenter.findingsEditor")
                .addMembers("user:" + userEmail)
                .build();
        Policy policy = oldPolicy.toBuilder().addBindings(bindings).build();
  
        // Start setting up a request to set IAM policy for a source.
        // SourceName sourceName = SourceName.of("123234324", "423432321");
        SetIamPolicyRequest.Builder request =
            SetIamPolicyRequest.newBuilder().setPolicy(policy).setResource(sourceName.toString());
  
        // Call the API.
        Policy response = client.setIamPolicy(request.build());
  
        System.out.println("Policy: " + response);
        return response;
      } catch (IOException e) {
        throw new RuntimeException("Couldn't create client.", e);
      }
    }