Document System.Linq.IQueryable<TSource> (#3672)

Author: carlossanlop

xml/System.Linq/Queryable.xml

@@ -508,12 +508,14 @@
         <Parameter Name="element" Type="TSource" Index="1" FrameworkAlternate="netcore-2.0;netcore-2.1;netcore-2.2;netcore-3.0;netstandard-2.1;netcore-3.1" />
       </Parameters>
       <Docs>
-        <typeparam name="TSource">To be added.</typeparam>
-        <param name="source">To be added.</param>
-        <param name="element">To be added.</param>
-        <summary>To be added.</summary>
-        <returns>To be added.</returns>
+        <typeparam name="TSource">The type of the elements in the queryable sequence.</typeparam>
+        <param name="source">A queryable sequence.</param>
+        <param name="element">An element of type <typeparamref name="TSource" /> to append to <paramref name="source" />.</param>
+        <summary>Returns a new queryable sequence that contains the elements from <paramref name="source" /> plus the specified <paramref name="element" /> appended at the end.</summary>
+        <returns>A new queryable sequence that contains the elements from <paramref name="source" /> plus the specified <paramref name="element" /> appended at the end.</returns>
         <remarks>To be added.</remarks>
+        <exception cref="T:System.ArgumentNullException">
+          <paramref name="source" /> is <see langword="null" />.</exception>
       </Docs>
     </Member>
     <Member MemberName="AsQueryable">
@@ -5160,12 +5162,14 @@
         <Parameter Name="element" Type="TSource" Index="1" FrameworkAlternate="netcore-2.0;netcore-2.1;netcore-2.2;netcore-3.0;netstandard-2.1;netcore-3.1" />
       </Parameters>
       <Docs>
-        <typeparam name="TSource">To be added.</typeparam>
-        <param name="source">To be added.</param>
-        <param name="element">To be added.</param>
-        <summary>To be added.</summary>
-        <returns>To be added.</returns>
+        <typeparam name="TSource">The type of the elements in the queryable sequence.</typeparam>
+        <param name="source">A queryable sequence.</param>
+        <param name="element">An element of type <typeparamref name="TSource" /> to prepend to <paramref name="source" />.</param>
+        <summary>Returns a new queryable sequence that contains the elements from <paramref name="source" /> plus the specified <paramref name="element" /> prepended at the beginning.</summary>
+        <returns>A new queryable sequence that contains the elements from <paramref name="source" /> plus the specified <paramref name="element" /> prepended at the beginning.</returns>
         <remarks>To be added.</remarks>
+        <exception cref="T:System.ArgumentNullException">
+          <paramref name="source" /> is <see langword="null" />.</exception>
       </Docs>
     </Member>
     <Member MemberName="Reverse&lt;TSource&gt;">
@@ -6175,12 +6179,22 @@
         <Parameter Name="count" Type="System.Int32" Index="1" FrameworkAlternate="netcore-2.0;netcore-2.1;netcore-2.2;netcore-3.0;netstandard-2.1;netcore-3.1" />
       </Parameters>
       <Docs>
-        <typeparam name="TSource">To be added.</typeparam>
-        <param name="source">To be added.</param>
-        <param name="count">To be added.</param>
-        <summary>To be added.</summary>
-        <returns>To be added.</returns>
-        <remarks>To be added.</remarks>
+        <typeparam name="TSource">The type of the elements in the queryable sequence.</typeparam>
+        <param name="source">A queryable sequence.</param>
+        <param name="count">The number of elements to omit from the end of the queryable sequence.</param>
+        <summary>Returns a new queryable sequence that contains the elements from <paramref name="source" /> with the last <paramref name="count" /> elements of the source queryable sequence omitted.</summary>
+        <returns>A new queryable sequence that contains the elements from <paramref name="source" /> minus <paramref name="count" /> elements from the end of the queryable sequence.</returns>
+        <remarks>
+          <format type="text/markdown"><![CDATA[
+
+## Remarks
+
+If `count` is not a positive number, this method returns an identical copy of the `source` queryable sequence.
+
+          ]]></format>
+        </remarks>
+        <exception cref="T:System.ArgumentNullException">
+          <paramref name="source" /> is <see langword="null" />.</exception>
       </Docs>
     </Member>
     <MemberGroup MemberName="SkipWhile&lt;TSource&gt;">
@@ -7695,12 +7709,22 @@
         <Parameter Name="count" Type="System.Int32" Index="1" FrameworkAlternate="netcore-2.0;netcore-2.1;netcore-2.2;netcore-3.0;netstandard-2.1;netcore-3.1" />
       </Parameters>
       <Docs>
-        <typeparam name="TSource">To be added.</typeparam>
-        <param name="source">To be added.</param>
-        <param name="count">To be added.</param>
-        <summary>To be added.</summary>
-        <returns>To be added.</returns>
-        <remarks>To be added.</remarks>
+        <typeparam name="TSource">The type of the elements in the queryable sequence.</typeparam>
+        <param name="source">A queryable sequence instance.</param>
+        <param name="count">The number of elements to take from the end of the queryable sequence.</param>
+        <summary>Returns a new queryable sequence that contains the last <paramref name="count" /> elements from <paramref name="source" />.</summary>
+        <returns>A new queryable sequence that contains the last <paramref name="count" /> elements from <paramref name="source" />.</returns>
+        <remarks>
+          <format type="text/markdown"><![CDATA[
+
+## Remarks
+
+If `count` is not a positive number, this method returns an empty queryable sequence.
+
+          ]]></format>
+        </remarks>
+        <exception cref="T:System.ArgumentNullException">
+          <paramref name="source" /> is <see langword="null" />.</exception>
       </Docs>
     </Member>
     <MemberGroup MemberName="TakeWhile&lt;TSource&gt;">