code: public float optFloat(int index, float defaultValue) {
          final Number val = this.optNumber(index, null);
          if (val == null) {
              return defaultValue;
          }
          final float floatValue = val.floatValue();
          // if (Float.isNaN(floatValue) || Float.isInfinite(floatValue)) {
          // return floatValue;
          // }
          return floatValue;
      }
docs: Get the optional float value associated with an index. The defaultValue
  is returned if there is no value for the index, or if the value is not a
  number and cannot be converted to a number.
  
  @param index
  subscript
  @param defaultValue
  The default value.
  @return The value.