final String value = namedItem.getTextContent();
        if (value == null) {
            return null;
        }
        try {
            return Integer.parseInt(value);
        } catch (final NumberFormatException e) {
            if (value.endsWith("%") || value.endsWith("px")) {
                return null;
            }
            return 0;
        }
    }

      // TODO(lowasser): could be potentially optimized, but only with
      // extensive testing
      try {
        return Float.parseFloat(string);
      } catch (NumberFormatException e) {
        // Float.parseFloat has changed specs several times, so fall through
        // gracefully
      }
    }
    return null;
  }

      // TODO(lowasser): could be potentially optimized, but only with
      // extensive testing
      try {
        return Double.parseDouble(string);
      } catch (NumberFormatException e) {
        // Double.parseDouble has changed specs several times, so fall through
        // gracefully
      }
    }
    return null;
  }

      // TODO(lowasser): could be potentially optimized, but only with
      // extensive testing
      try {
        return Float.parseFloat(string);
      } catch (NumberFormatException e) {
        // Float.parseFloat has changed specs several times, so fall through
        // gracefully
      }
    }
    return null;
  }

      // TODO(lowasser): could be potentially optimized, but only with
      // extensive testing
      try {
        return Double.parseDouble(string);
      } catch (NumberFormatException e) {
        // Double.parseDouble has changed specs several times, so fall through
        // gracefully
      }
    }
    return null;
  }

  }

  /**
   * Returns a serializable converter object that converts between strings and longs using {@link
   * Long#decode} and {@link Long#toString()}. The returned converter throws {@link
   * NumberFormatException} if the input string is invalid.
   *
   * <p><b>Warning:</b> please see {@link Long#decode} to understand exactly how strings are parsed.

  }

  /**
   * Returns a serializable converter object that converts between strings and longs using {@link
   * Long#decode} and {@link Long#toString()}. The returned converter throws {@link
   * NumberFormatException} if the input string is invalid.
   *
   * <p><b>Warning:</b> please see {@link Long#decode} to understand exactly how strings are parsed.

                return Integer.valueOf(from);
              }
            });

    Iterator<Integer> resultIterator = result.iterator();
    resultIterator.next();

    assertThrows(NumberFormatException.class, () -> resultIterator.next());
  }

  public void testNullFriendlyTransform() {
    List<@Nullable Integer> input = asList(1, 2, null, 3);
    Iterable<String> result =
        Iterables.transform(

                    key = fieldName.substring(fieldName.lastIndexOf('[') + 1, fieldName.length() - 1);
                    try {
                        key = Integer.valueOf(key.toString());
                    } catch (NumberFormatException e) {
                        // use key as is
                    }
                }

                location = tracker.getLocation(key);
            }

            if (location == null) {

              @Override
              public Integer apply(String from) {
                return Integer.valueOf(from);
              }
            });

    result.next();
    assertThrows(NumberFormatException.class, () -> result.next());
  }

  public void testNullFriendlyTransform() {
    Iterator<@Nullable Integer> input = Arrays.<@Nullable Integer>asList(1, 2, null, 3).iterator();
    Iterator<String> result =