code: public Float getFloat (String key, Supplier<Float> notFound) {
          return getParsed (key, Float::new, notFound);
      }
docs: Retrieve a mapped element and return it as a Float.
  
  @param key A string value used to index the element.
  @param notFound A function to create a new Float if the requested key was not found
  @return The element as a Float, or notFound if the element is not found.