docs: public FieldInfo getDeclaredFieldInfo(final String fieldName) {
          if (!scanResult.scanSpec.enableFieldInfo) {
              throw new IllegalArgumentException("Please call ClassGraph#enableFieldInfo() before #scan()");
          }
          if (fieldInfo == null) {
              return null;
          }
          for (final FieldInfo fi : fieldInfo) {
              if (fi.getName().equals(fieldName)) {
                  return fi;
              }
          }
          return null;
      }