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());
        assertEquals("SOURCE_PROBLEM2", collector.getProblems().get(1).getSource());

            locations.putAll(sourceDominant ? sourceLocations : targetLocations);
        }

        return new InputLocation(-1, -1, InputSource.merge(source.getSource(), target.getSource()), locations);
    } // -- InputLocation merge( InputLocation, InputLocation, boolean )

    /**
     * Merges the {@code source} location into the {@code target} location.

     *
     * @return The hint about the source of the problem or an empty string if unknown, never {@code null}.
     */
    String getSource();

    /**
     * Gets the one-based index of the line containing the problem. The line number should refer to some text file that
     * is given by {@link #getSource()}.
     *
     * @return The one-based index of the line containing the problem or a non-positive value if unknown.
     */

                            md.getClassifier(),
                            edge.getArtifactUri(),
                            edge.getSource() == null
                                    ? ""
                                    : edge.getSource().getMd().toString(),
                            edge.isResolved(),
                            edge.getTarget() == null
                                    ? null

// Tests getSource().
func TestGetSource(t *testing.T) {
	currentSource := func() string { return getSource(2) }
	gotSource := currentSource()
	// Hard coded line number, 34, in the "expectedSource" value
	expectedSource := "[namespace-lock_test.go:34:TestGetSource()]"
	if gotSource != expectedSource {
		t.Errorf("expected : %s, got : %s", expectedSource, gotSource)
	}
}

// Test lock race

    @Override
    public String getLocation() {
        StringBuilder buffer = new StringBuilder(256);

        if (!getSource().isEmpty()) {
            if (!buffer.isEmpty()) {
                buffer.append(", ");
            }
            buffer.append(getSource());
        }

        if (getLineNumber() > 0) {
            if (!buffer.isEmpty()) {
                buffer.append(", ");
            }

     * @return the hint about the source of the problem or an empty string if unknown, never {@code null}
     */
    @Nonnull
    String getSource();

    /**
     * Gets the one-based index of the line containing the problem. The line number should refer to some text file that
     * is given by {@link #getSource()}.
     *
     * @return the one-based index of the line containing the problem or a non-positive value if unknown
     */

        Profile existing = profilesById.get(profileId);
        if (existing != null) {
            logger.warn("Overriding profile: '" + profileId + "' (source: " + existing.getSource()
                    + ") with new instance from source: " + profile.getSource());
        }

        profilesById.put(profile.getId(), profile);

        Activation activation = profile.getActivation();

        assertThrows(
            ConflictingRequirementsException.class, () -> buildTesterRequirements(Tester.class));
    assertThat(e.getConflicts()).containsExactly(FOO);
    assertThat(e.getSource()).isEqualTo(Tester.class.getAnnotation(Require.class));
  }

  public void testBuildTesterRequirements_classClassConflict_inherited() {
    @Require(FOO)
    abstract class BaseTester {}
    @Require(absent = FOO)

        assertEquals("", problem.getSource());

        problem = new DefaultProblem(null, null, "", -1, -1, null);
        assertEquals("", problem.getSource());

        problem = new DefaultProblem(null, null, "SOURCE", -1, -1, null);
        assertEquals("SOURCE", problem.getSource());
    }

    @Test
    void testGetLocation() {