code: public static OptionalFloat createFloat(final String str) {
          if (N.isNullOrEmpty(str)) {
              return OptionalFloat.empty();
          }
  
          try {
              return OptionalFloat.of(Float.parseFloat(str));
          } catch (NumberFormatException e) {
              return OptionalFloat.empty();
          }
      }
docs: <p>
  Convert a <code>String</code> to a <code>Float</code>.
  </p>
  
  <p>
  Returns an empty {@code OptionalFloat} if the string is {@code null} or can't be parsed as {@code Float}.
  </p>
  
  @param str a <code>String</code> to convert, may be null
  @return