applyMatrix4( matrix ) {

		const start = this.attributes.instanceStart;
		const end = this.attributes.instanceEnd;

		if ( start !== undefined ) {

			start.applyMatrix4( matrix );

			end.applyMatrix4( matrix );

			start.needsUpdate = true;

		}

		if ( this.boundingBox !== null ) {

			this.computeBoundingBox();

		}

		if ( this.boundingSphere !== null ) {

			this.computeBoundingSphere();

		}

		return this;

	}
Applies the given 4x4 transformation matrix to the geometry.

@param {Matrix4} matrix - The matrix to apply.
@return {LineSegmentsGeometry} A reference to this instance.