diff --git a/library/alloc/src/collections/btree/map.rs b/library/alloc/src/collections/btree/map.rs
index ff908ec12ec..29e9423bb43 100644
--- a/library/alloc/src/collections/btree/map.rs
+++ b/library/alloc/src/collections/btree/map.rs
@@ -613,8 +613,6 @@ impl<K, V> BTreeMap<K, V> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// use std::collections::BTreeMap;
     ///
@@ -636,8 +634,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// use std::collections::BTreeMap;
     ///
@@ -661,8 +657,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// # #![feature(allocator_api)]
     /// # #![feature(btreemap_alloc)]
@@ -688,8 +682,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// use std::collections::BTreeMap;
     ///
@@ -744,8 +736,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// use std::collections::BTreeMap;
     ///
@@ -830,8 +820,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// use std::collections::BTreeMap;
     ///
@@ -917,8 +905,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// use std::collections::BTreeMap;
     ///
@@ -943,8 +929,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// use std::collections::BTreeMap;
     ///
@@ -982,8 +966,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// use std::collections::BTreeMap;
     ///
@@ -1017,8 +999,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// #![feature(map_try_insert)]
     ///
@@ -1051,8 +1031,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// use std::collections::BTreeMap;
     ///
@@ -1078,8 +1056,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// use std::collections::BTreeMap;
     ///
@@ -1208,8 +1184,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// use std::collections::BTreeMap;
     /// use std::ops::Bound::Included;
@@ -1251,8 +1225,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// use std::collections::BTreeMap;
     ///
@@ -1283,8 +1255,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// use std::collections::BTreeMap;
     ///
@@ -1336,8 +1306,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// use std::collections::BTreeMap;
     ///
@@ -2388,8 +2356,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// use std::collections::BTreeMap;
     ///
@@ -2420,8 +2386,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// use std::collections::BTreeMap;
     ///
@@ -2453,8 +2417,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// use std::collections::BTreeMap;
     ///
@@ -2474,8 +2436,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// use std::collections::BTreeMap;
     ///
@@ -2495,8 +2455,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// use std::collections::BTreeMap;
     ///
@@ -2521,8 +2479,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// use std::collections::BTreeMap;
     ///
@@ -2546,8 +2502,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// use std::collections::BTreeMap;
     ///
@@ -2578,8 +2532,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// #![feature(btree_cursors)]
     ///
@@ -2619,8 +2571,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// #![feature(btree_cursors)]
     ///
@@ -2673,8 +2623,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// #![feature(btree_cursors)]
     ///
@@ -2714,8 +2662,6 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// # Examples
     ///
-    /// Basic usage:
-    ///
     /// ```
     /// #![feature(btree_cursors)]
     ///