init research

dataframe/plugins/kotlin-dataframe/testData/box/insertAfter.kt

@@ -0,0 +1,12 @@
+import org.jetbrains.kotlinx.dataframe.*
+import org.jetbrains.kotlinx.dataframe.api.*
+
+fun box(): String {
+    val df = dataFrameOf("a", "b", "c")(1, 2, 3, 4, 5, 6)
+
+    val dfWithD = df.insert("d") { b * c }.after { a }
+
+    val dCol: DataColumn<Int> = dfWithD.d
+
+    return "OK"
+}