From b3fb98d1bb214355c19090146def8dfd43b0c13a Mon Sep 17 00:00:00 2001
From: David Kale <dakale@github.com>
Date: Tue, 4 Feb 2020 15:27:30 -0500
Subject: [PATCH] Case insensitive check for existing header

---
 index.ts | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/index.ts b/index.ts
index c21fd44..852f53a 100644
--- a/index.ts
+++ b/index.ts
@@ -433,9 +433,11 @@ export class HttpClient {
     }
 
     private _getExistingOrDefaultHeader(additionalHeaders: ifm.IHeaders, header: string, _default: string) {
+        const lowercaseKeys = obj => Object.keys(obj).reduce((c, k) => (c[k.toLowerCase()] = obj[k], c), {});
+
         let clientHeader: string;
         if(this.requestOptions && this.requestOptions.headers) {
-            clientHeader =  this.requestOptions.headers[header];
+            clientHeader =  lowercaseKeys(this.requestOptions.headers)[header];
         }
         return additionalHeaders[header] || clientHeader || _default;
     }