code: function writeMultiLineStringGeometry_(geometry) {
    if (geometry instanceof olGeomMultiLineString) {
      const ends = geometry.getEnds();
      const lineStringCount = ends.length;
      const flatCoordinates = geometry.getFlatCoordinates();
      const stride = geometry.getStride();
      let offset = 0;
      const textArray = ['L('];
      for (let i = 0; i < lineStringCount; ++i) {
        const end = ends[i];
        const text = this.encodeCoordinates_(flatCoordinates, stride, offset, end);
        if (i !== 0) {
          textArray.push('\'');
        }
        textArray.push(text);
        offset = end;
      }
      textArray.push(')');
      return textArray.join('');
    }
    return null;
  }
docs: Encode a {@link import("ol/geom/MultiLineString.js").default} geometry into a logical sequence
  of characters.
  @param {Geometry} geometry Geometry.
  @return {?string} Encoded geometry.
  @private
  @hidden
  @this {FeatureHash}