Feature: getNoBidsForAdUnitCode (prebid#2498)

* added getNoBidsForAdUnitCode

* added request params to docs

* adjusted getNoBids doc to say it returns an object

dev-docs/publisher-api-reference.md

@@ -29,6 +29,7 @@ This page has documentation for the public API methods of Prebid.js.
   * [.getAllWinningBids()](#module_pbjs.getAllWinningBids)
   * [.getAllPrebidWinningBids()](#module_pbjs.getAllPrebidWinningBids)
   * [.getNoBids()](#module_pbjs.getNoBids)
+  * [.getNoBidsForAdUnitCode(adUnitCode)](#module_pbjs.getNoBidsForAdUnitCode)
   * [.setTargetingForGPTAsync([codeArr], customSlotMatching)](#module_pbjs.setTargetingForGPTAsync)
   * [.setTargetingForAst()](#module_pbjs.setTargetingForAst)
   * [.renderAd(doc, id)](#module_pbjs.renderAd)
@@ -574,14 +575,33 @@ pbjs.refreshUserIds({ submoduleNames: ['britepoolId'] }, () => console.log("Done
 
 <a name="module_pbjs.getNoBids"></a>
 
-### pbjs.getNoBids() ⇒ `Array`
+### pbjs.getNoBids() ⇒ `Object`
 
 Use this method to get all of the bid requests that resulted in a NO_BID.  These are bid requests that were sent to a bidder but, for whatever reason, the bidder decided not to bid on.  Used by debugging snippet in [Tips for Troubleshooting](/dev-docs/troubleshooting-tips.html).
 
 + `pbjs.getNoBids()`: returns an array of bid request objects that were deliberately not bid on by a bidder.
 
 <hr class="full-rule">
 
+<a name="module_pbjs.getNoBidsForAdUnitCode"></a>
+
+### pbjs.getNoBidsForAdUnitCode(adUnitCode) ⇒ `Object`
+
+Returns bid requests that resulted in a NO_BID for the specified adUnitCode.  See full documentation at [pbjs.getNoBids()](#module_pbjs.getNoBids).
+
+**Kind**: static method of [pbjs](#module_pbjs)
+
+**Returns**: `Object` - NO_BID bidResponse object
+
+**Request Params:**
+
+{: .table .table-bordered .table-striped }
+| Param | Scope | Type | Description |
+| --- | --- | --- | --- |
+| adUnitCode | Required | `String` | adUnitCode |
+
+<hr class="full-rule">
+
 <a name="module_pbjs.setTargetingForGPTAsync"></a>
 
 ### pbjs.setTargetingForGPTAsync([codeArr], customSlotMatching)