API Reference > geometry-core > Bspline > BSpline1dNd > testCloseablePolygon testCloseablePolygon Method Test if the leading and trailing polygon coordinates are replicated in the manner of a "closed" bspline polygon which has been expanded to act as a normal bspline. testCloseablePolygon(mode?: BSplineWrapMode): boolean Parameter Type Description mode BSplineWrapMode Returns - boolean true if degree leading and trailing polygon blocks match Defined in core/geometry/src/bspline/BSpline1dNd.ts Line 187 Last Updated: 15 June, 2021