* track the problem back to its origin. A concrete example for such a source hint can be the file path or URL from
     * which the settings were read.
     *
     * @return the hint about the source of the problem or an empty string if unknown, never {@code null}
     */
    @Nonnull
    String getSource();

    /**

        try (InputStream fis = Files.newInputStream(path)) {
            byte[] buffer = new byte[SHA1_BUFFER_SIZE];
            int read;
            while ((read = fis.read(buffer)) != -1) {
                md.update(buffer, 0, read);
            }
        }
        StringBuilder result = new StringBuilder();
        for (byte b : md.digest()) {
            result.append(String.format("%02x", b));

    public void clear() {
      ReferenceEntry<K, V> e = head.getNextInWriteQueue();
      while (e != head) {
        ReferenceEntry<K, V> next = e.getNextInWriteQueue();
        nullifyWriteOrder(e);
        e = next;
      }

      head.setNextInWriteQueue(head);
      head.setPreviousInWriteQueue(head);
    }

    @Override
    public Iterator<ReferenceEntry<K, V>> iterator() {

      current = it.next().openStream();
    }
  }

  @Override
  public int read(char[] cbuf, int off, int len) throws IOException {
    checkNotNull(cbuf);
    if (current == null) {
      return -1;
    }
    int result = current.read(cbuf, off, len);
    if (result == -1) {
      advance();
      return read(cbuf, off, len);
    }
    return result;
  }

  @Override

   * isWellFormed(bytes)} is true.
   *
   * @param bytes the input buffer
   * @param off the offset in the buffer of the first byte to read
   * @param len the number of bytes to read from the buffer
   */
  public static boolean isWellFormed(byte[] bytes, int off, int len) {
    int end = off + len;
    checkPositionIndexes(off, end, bytes.length);

                } catch (final Exception e) {
                    logger.log(Level.WARNING, e, () -> {
                        final String canonicalPath = possibleJar.getCanonicalPath();
                        return "Failed to read " + canonicalPath;
                    });
                }
            }
        }
    }

        MavenStaxReader modelReader = new MavenStaxReader();
        try {
            model = new Model(modelReader.read(sReader));
        } catch (XMLStreamException e) {
            throw new ModelInterpolationException(
                    "Cannot read project model from interpolating filter of serialized version.", e);
        }

        return model;
    }

    /**

                } catch (final Exception e) {
                    logger.warn("Failed to read a click log: {}", list, e);
                }
            }
        } catch (final IOException e) {
            logger.warn("Failed to read a click log.", e);
        }
    }

    public void exportCsv(final Writer writer) {

      this.map =
          MapMakerInternalMap.createWithDummyValues(mapMaker.keyEquivalence(Equivalence.equals()));
    }

    @Override
    public E intern(E sample) {
      while (true) {
        // trying to read the canonical...
        @SuppressWarnings("rawtypes") // using raw types to avoid a bug in our nullness checker :(
        InternalEntry entry = map.getEntry(sample);
        if (entry != null) {

        // phase 1
        DefaultModelBuilderResult result = new DefaultModelBuilderResult();

        DefaultModelProblemCollector problems = new DefaultModelProblemCollector(result);

        // read and validate raw model
        Model fileModel = readFileModel(request, problems);
        result.setFileModel(fileModel);

        Model activatedFileModel = activateFileModel(fileModel, request, result, problems);