add toMulti extensions

Author: AndreiKingsley

dataframe-geo/src/main/kotlin/org/jetbrains/kotlinx/dataframe/geo/jts/toMulti.kt

@@ -0,0 +1,41 @@
+package org.jetbrains.kotlinx.dataframe.geo.jts
+
+import org.locationtech.jts.geom.LineString
+import org.locationtech.jts.geom.MultiLineString
+import org.locationtech.jts.geom.MultiPoint
+import org.locationtech.jts.geom.MultiPolygon
+import org.locationtech.jts.geom.Point
+import org.locationtech.jts.geom.Polygon
+
+/**
+ * Converts a [Polygon] to a [MultiPolygon] by wrapping it in a MultiPolygon.
+ *
+ * @receiver Polygon to be converted.
+ * @return A MultiPolygon containing the original Polygon.
+ */
+fun Polygon.toMultiPolygon(): MultiPolygon {
+    val geometryFactory = this.factory
+    return geometryFactory.createMultiPolygon(arrayOf(this))
+}
+
+/**
+ * Converts a [Point] to a [MultiPoint] by wrapping it in a MultiPoint.
+ *
+ * @receiver Point to be converted.
+ * @return A MultiPoint containing the original Point.
+ */
+fun Point.toMultiPoint(): MultiPoint {
+    val geometryFactory = this.factory
+    return geometryFactory.createMultiPoint(arrayOf(this))
+}
+
+/**
+ * Converts a [LineString] to a [MultiLineString] by wrapping it in a MultiLineString.
+ *
+ * @receiver LineString to be converted.
+ * @return A MultiLineString containing the original LineString.
+ */
+fun LineString.toMultiLineString(): MultiLineString {
+    val geometryFactory = this.factory
+    return geometryFactory.createMultiLineString(arrayOf(this))
+}