set custom header method

Author: saeed-rz

library/src/main/java/com/loopj/android/http/AsyncHttpClient.java

@@ -36,6 +36,7 @@
 import java.net.URI;
 import java.net.URL;
 import java.net.URLDecoder;
+import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
@@ -370,6 +371,12 @@ public void setEnableRedirectStrategy(boolean isEnable){
         }
     }
 
+    public void setCustomHeaders(Collection<? extends Header> headers){
+        if (getHttpClientProvider() instanceof DefaultHttpClientProvider) {
+            ((DefaultHttpClientProvider) getHttpClientProvider()).setHeaders(headers);
+        }
+    }
+
     /**
      * @deprecated
      */

library/src/main/java/com/loopj/android/http/DefaultHttpClientProvider.java

@@ -39,7 +39,7 @@ public class DefaultHttpClientProvider implements HttpClientProviderInterface {
     protected HttpHost proxy;
     protected CookieStore cookieStore;
     protected CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
-    protected final Collection<? extends Header> commonHeaders = new ArrayList<Header>();
+    protected final Collection<Header> commonHeaders = new ArrayList<Header>();
     protected HttpRequestRetryHandler retryHandler;
     protected boolean enableRedirects = false, enableRelativeRedirects = false, enableCircularRedirects = false;
     protected RedirectStrategy redirectStrategy;
@@ -107,7 +107,7 @@ public void setCookieStore(CookieStore store) {
         cookieStore = store;
     }
 
-    public Collection<? extends Header> getHeaders() {
+    public Collection<Header> getHeaders() {
         return commonHeaders;
     }
 
@@ -133,4 +133,8 @@ public boolean isEnableRedirectStrategy() {
     public void setEnableRedirectStrategy(boolean enableRedirectStrategy) {
         this.enableRedirectStrategy = enableRedirectStrategy;
     }
+
+    public void setHeaders(Collection<? extends Header> headers){
+        commonHeaders.addAll(headers);
+    }
 }