* This is the main trigger for the <code>Mojo</code> inside the <code>Maven</code> system, and allows
     * the <code>Mojo</code> to communicate errors.
     *
     * @throws MojoException if a problem occurs
     */
    void execute();

    // <plugin/> block in a Maven POM. We have to do some wiggling to pull the sources of information
    // together and this really shows the problem of constructing a sensible default configuration but
    // it's all encapsulated here so it appears normalized to the POM builder.

                sb.append(problem.getSeverity());
                sb.append("] ");
                sb.append(problem.getMessage());
                String loc = Stream.of(
                                problem.getModelId().equals(modelId) ? problem.getModelId() : "",
                                problem.getModelId().equals(modelId) ? problem.getSource() : "",

                        return defaultModelBuilder.readRawModel(gaBuildingRequest, problems);
                    } catch (ModelBuilderException e) {
                        // gathered with problem collector
                    }
                }
                return null;
            }

            private void loadFullReactor() {
                if (!fullReactorLoaded) {

            if (cause instanceof ModelBuildingException) {
                String message = "In: " + pom + "\n\n";
                for (ModelProblem problem : ((ModelBuildingException) cause).getProblems()) {
                    message += problem + "\n";
                }
                System.out.println(message);
                fail(message);
            }

            throw e;
        }
    }

     * @return The calculated checksums, indexed by algorithms, never {@code null}.
     * @throws NullPointerException if passed in any parameter is {@code null}.
     * @throws IOException In case of any IO problem.
     */
    @Nonnull
    Map<ChecksumAlgorithm, String> calculate(@Nonnull Path file, @Nonnull Collection<ChecksumAlgorithm> algorithms)
            throws IOException;

    /**

 */
package org.apache.maven.building;

/**
 * Describes a problem that was encountered during settings building. A problem can either be an exception that was
 * thrown or a simple string message. In addition, a problem carries a hint about its source, e.g. the settings file
 * that exhibits the problem.
 *
 */
class DefaultProblem implements Problem {

    private final String source;

    private final int lineNumber;

 * 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
 * it delegates to other components that potentially encounter problems. Then, the problem reporter can focus on

import org.apache.maven.api.services.BuilderProblem;

/**
 * Describes a problem that was encountered during settings building. A problem can either be an exception that was
 * thrown or a simple string message. In addition, a problem carries a hint about its source, e.g. the settings file
 * that exhibits the problem.
 */
class DefaultBuilderProblem implements BuilderProblem {
    final String source;

    @Test
    void testNewInstance() {
        ProblemCollector collector1 = ProblemCollectorFactory.newInstance(null);

        Problem problem = new DefaultProblem("MESSAGE1", null, null, -1, -1, null);
        ProblemCollector collector2 = ProblemCollectorFactory.newInstance(Collections.singletonList(problem));

        assertNotSame(collector1, collector2);
        assertEquals(0, collector1.getProblems().size());