import org.apache.maven.api.model.Model;

/**
 * Collects problems that are encountered during model building. The primary purpose of this component is to account for
 * the fact that the problem reporter has/should not have information about the calling context and hence cannot provide
 * an expressive source hint for the model problem. Instead, the source hint is configured by the model builder before

 * providing a simple error message, leaving the donkey work of creating a nice model problem to this component.
 *
 * @deprecated use {@code org.apache.maven.api.services.ModelBuilder} instead
 */
@Deprecated(since = "4.0.0")
public interface ModelProblemCollector {

    /**
     * Adds the specified problem.
     *
     * @param req must not be null
     */

        assertEquals(
                "1 problem was encountered while building the effective toolchains" + LS
                        + "[ERROR] MESSAGE @ line 3, column 5" + LS,
                e.getMessage());
    }

    @Test
    void testUnknownPositionAndSource() {
        ProblemCollector problemCollector = ProblemCollectorFactory.newInstance(null);
        problemCollector.add(Problem.Severity.ERROR, "MESSAGE", -1, -1, new Exception());

        - Typo (please open a PR instead)
    validations:
      required: true
  - type: textarea
    id: description
    attributes:
      label: Problem description
      description: |
        Please describe the problem as concisely as possible.
    validations:
      required: true
  - type: textarea
    id: context
    attributes:
      label: Context (optional)
      description: |

    private List<Problem> problems;

    /**
     * Default constructor
     *
     * @param effectiveToolchains the merged toolchains, may not be {@code null}
     * @param problems the problems while building the effectiveToolchains, if any.
     */
    public DefaultToolchainsBuildingResult(PersistedToolchains effectiveToolchains, List<Problem> problems) {
        this.effectiveToolchains = effectiveToolchains;

     * @return The formatted problem location or an empty string if unknown, never {@code null}.
     */
    public static String formatLocation(ModelProblem problem, String projectId) {
        StringBuilder buffer = new StringBuilder(256);

        if (!problem.getModelId().equals(projectId)) {
            buffer.append(problem.getModelId());

            if (!problem.getSource().isEmpty()) {

A clear and concise description of what you expected to happen.

**Screenshots**
If applicable, add screenshots to help explain your problem.

**Environment (please complete the following information):**
 - OS: [e.g. Windows 10]
 - Version [e.g. 3.5.0]

**Additional context**

     * @param problems the collection of problems to include in the message
     * @return a formatted message including details of all problems
     */
    protected static String buildMessage(String message, ProblemCollector<BuilderProblem> problems) {
        StringBuilder msg = new StringBuilder(message);
        problems.problems().forEach(problem -> msg.append("\n * ")
                .append(problem.getSeverity().name())

        DefaultProblemCollector collector = new DefaultProblemCollector(null);

        collector.add(null, "PROBLEM1", -1, -1, null);

        collector.setSource("SOURCE_PROBLEM2");
        collector.add(null, "PROBLEM2", -1, -1, null);

        collector.setSource("SOURCE_PROBLEM3");
        collector.add(null, "PROBLEM3", -1, -1, null);

        assertEquals("", collector.getProblems().get(0).getSource());

**Plugins installed**: []

**JVM version** (`java -version`):

**OS version** (`uname -a` if on a Unix-like system):

**Description of the problem including expected versus actual behavior**:

**Steps to reproduce**:

Please include a *minimal* but *complete* recreation of the problem,
including (e.g.) index creation, mappings, settings, query etc.  The easier
you make for us to reproduce it, the more likely that somebody will take the