getCoordinateAt(fraction, dest) {
    return interpolatePoint(
      this.flatCoordinates,
      0,
      this.flatCoordinates.length,
      this.stride,
      fraction,
      dest,
      this.stride,
    );
  }
Return the coordinate at the provided fraction along the linestring.
The `fraction` is a number between 0 and 1, where 0 is the start of the
linestring and 1 is the end.
@param {number} fraction Fraction.
@param {import("../coordinate.js").Coordinate} [dest] Optional coordinate whose values will
    be modified. If not provided, a new coordinate will be returned.
@return {import("../coordinate.js").Coordinate} Coordinate of the interpolated point.
@api