code: public static final float getFloatAttribute(Path path, String attribute, LinkOption... options) throws IOException
      {
          return getFloatAttribute(path, attribute, Float.NaN, options);
      }
docs: Returns user-defined-attribute NaN if not found.
  @param path
  @param attribute
  @param options
  @return
  @throws IOException
  @see java.lang.Float#NaN