hg: jdk9/sandbox/jdk: http-client-branch: Make sure UnsupportedOperationException is thrown on any attempt to modify ResponseHeaders

[pavel.rappo at oracle.com]

Changeset: 061d9aee168b
Author:    prappo
Date:      2016-08-23 12:28 +0100
URL:       http://hg.openjdk.java.net/jdk9/sandbox/jdk/rev/061d9aee168b

http-client-branch: Make sure UnsupportedOperationException is thrown on any attempt to modify ResponseHeaders

! src/java.httpclient/share/classes/java/net/http/ResponseHeaders.java
! test/java/net/httpclient/HeadersTest1.java
! test/java/net/httpclient/TestKit.java
! test/java/net/httpclient/TestKitTest.java