* value is undefined.
     *
     * @return the location of the problem, never {@code null}
     */
    @Nonnull
    String getLocation();

    /**
     * Gets the exception that caused this problem (if any).
     *
     * @return the exception that caused this problem or {@code null} if not applicable
     */
    @Nullable

     *   <li>Description: {@code <memory>} or {@code <database>}</li>
     * </ul>
     *
     * @return a non-null string describing the source location
     */
    @Nonnull
    String getLocation();

    /**
     * Resolves a new source relative to this one.
     * <p>
     * The resolution strategy depends on the source type:
     * <ul>
     *   <li>File sources resolve against their parent directory</li>

        @Nonnull
        public InputStream openStream() throws IOException {
            return Files.newInputStream(path);
        }

        @Override
        @Nonnull
        public String getLocation() {
            return location;
        }

        @Override
        @Nullable
        public Source resolve(@Nonnull String relative) {
            return new PathSource(path.resolve(relative));

            @Override
            public InputStream openStream() throws IOException {
                return Files.newInputStream(actual);
            }

            @Override
            public String getLocation() {
                return actual.toString();
            }

            @Override
            public Source resolve(String relative) {
                return Sources.buildSource(actual.resolve(relative));

            params.setIsRuntimeJavaHomeSet(Jvm.current().getJavaHome().equals(runtimeJavaHome) == false);
            JvmInstallationMetadata runtimeJdkMetaData = metadataDetector.getMetadata(getJavaInstallation(runtimeJavaHome).getLocation());
            params.setRuntimeJavaDetails(formatJavaVendorDetails(runtimeJdkMetaData));
            params.setJavaVersions(getAvailableJavaVersions());
            params.setMinimumCompilerVersion(minimumCompilerVersion);

        </field>
      </fields>
      <codeSegments>
        <codeSegment>
          <version>1.2.0+</version>
          <code>
    @Override
    public String toString() {
        return getLocation();
    }
          </code>
        </codeSegment>
      </codeSegments>
    </class>
  </classes>

        Source src = mock(Source.class);
        IOException ioException = new IOException("MESSAGE");
        doThrow(ioException).when(src).getInputStream();
        doReturn("LOCATION").when(src).getLocation();

        ToolchainsBuildingRequest request = new DefaultToolchainsBuildingRequest();
        request.setGlobalToolchainsSource(src);

        try {
            toolchainBuilder.build(request);

                source.setModelId(ModelProblemUtils.toId(model));
                source.setLocation(modelSource.getLocation());
            }
        } catch (ModelParseException e) {
            problems.add(new ModelProblemCollectorRequest(Severity.FATAL, Version.BASE)
                    .setMessage("Non-parseable POM " + modelSource.getLocation() + ": " + e.getMessage())
                    .setException(e));

        problems.add(new ModelProblemCollectorRequest(severity, version)
                .setMessage(buffer.toString())
                .setLocation(getLocation(fieldName, tracker)));
        // CHECKSTYLE_ON: LineLength
    }

    private static InputLocation getLocation(String fieldName, InputLocationTracker tracker) {
        InputLocation location = null;

        if (tracker != null) {

                slf4jLogger.warn("{} @ {}", problem.getMessage(), problem.getLocation());
            }

            slf4jLogger.warn("");
        }
    }

    private Object getLocation(Source source, File defaultLocation) {
        if (source != null) {
            return source.getLocation();
        }
        return defaultLocation;
    }