Add sample for Map.flatMap

libraries/stdlib/common/src/generated/_Maps.kt

@@ -40,7 +40,7 @@ public fun <K, V> Map<out K, V>.toList(): List<Pair<K, V>> {
 /**
  * Returns a single list of all elements yielded from results of [transform] function being invoked on each entry of original map.
  * 
- * @sample samples.collections.Collections.Transformations.flatMap
+ * @sample samples.collections.Maps.Transformations.flatMap
  */
 public inline fun <K, V, R> Map<out K, V>.flatMap(transform: (Map.Entry<K, V>) -> Iterable<R>): List<R> {
     return flatMapTo(ArrayList<R>(), transform)

libraries/stdlib/samples/test/samples/collections/maps.kt

@@ -353,7 +353,11 @@ class Maps {
             assertPrints(peopleToAge.map { it.value }, "[20, 21]")
         }
 
+        @Sample
+        fun flatMap() {
+            val map = mapOf("122" to 2, "3455" to 3)
+            assertPrints(map.flatMap { (key, value) -> key.take(value).toList() }, "[1, 2, 3, 4, 5]")
+        }
     }
-
 }
 

libraries/tools/kotlin-stdlib-gen/src/templates/Mapping.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2018 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
@@ -290,7 +290,13 @@ object Mapping : TemplateGroupBase() {
         specialFor(ArraysOfUnsigned) { inlineOnly() }
 
         doc { "Returns a single list of all elements yielded from results of [transform] function being invoked on each ${f.element} of original ${f.collection}." }
-        sample("samples.collections.Collections.Transformations.flatMap")
+
+        fun sampleClass(f: Family): String = when (f) {
+            Maps -> "samples.collections.Maps.Transformations"
+            else -> "samples.collections.Collections.Transformations"
+        }
+
+        sample("${sampleClass(f)}.flatMap")
         typeParam("R")
         returns("List<R>")
         body {