/android/content/Context.html?is-external=true" title="class or interface in android.content">Context</A>&nbsp;context,
                               <A target="_top" HREF="http://developer.android.com/reference/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A>&nbsp;channel)</PRE>
<DL>
<DD>Cancels a previous call to subscribe. If the user is not subscribed to this channel, this is a
 no-op. This call does not require internet access. It returns without blocking.
<P>