getFloat() {
    if (this.dataView_.byteLength == 4) {
      return this.dataView_.getFloat32(0);
    } else if (this.dataView_.byteLength == 8) {
      return this.dataView_.getFloat64(0);
    } else {
      throw new shaka.util.Error(
          shaka.util.Error.Severity.CRITICAL,
          shaka.util.Error.Category.MEDIA,
          shaka.util.Error.Code.EBML_BAD_FLOATING_POINT_SIZE);
    }
  }
Interpret the element's data as a floating point number
(32 bits or 64 bits). 80-bit floating point numbers are not supported.
@return {number}