getCoordinateAtM(m, extrapolate) {
    if (this.layout != 'XYM' && this.layout != 'XYZM') {
      return null;
    }
    extrapolate = extrapolate !== undefined ? extrapolate : false;
    return lineStringCoordinateAtM(
      this.flatCoordinates,
      0,
      this.flatCoordinates.length,
      this.stride,
      m,
      extrapolate,
    );
  }
Returns the coordinate at `m` using linear interpolation, or `null` if no
such coordinate exists.

`extrapolate` controls extrapolation beyond the range of Ms in the
MultiLineString. If `extrapolate` is `true` then Ms less than the first
M will return the first coordinate and Ms greater than the last M will
return the last coordinate.

@param {number} m M.
@param {boolean} [extrapolate] Extrapolate. Default is `false`.
@return {import("../coordinate.js").Coordinate|null} Coordinate.
@api