invokeAPI check against Family.SUCCESSFUL

I changed the the check against Family.SUCCESSFUL to catch all 2xx HTTP codes, the 201 Created, too.
According to DocuSign API it should be sufficient to detect successful cases.

Why I throw this exception to indicate a bad server response:
If we exit the method at line 757 or 760 with "return null;" we can not react on upper level in our application side based on HTTP code.
No indication is possible what's going wrong in that api call.

If this is not what you asked, please give me a hint ;-)

Author: psytester

src/main/java/com/docusign/esign/client/ApiClient.java

@@ -22,7 +22,6 @@
 import org.apache.oltu.oauth2.client.request.OAuthClientRequest.TokenRequestBuilder;
 import org.apache.oltu.oauth2.common.exception.OAuthSystemException;
 
-import javax.ws.rs.core.Response.Status;
 import javax.ws.rs.core.Response.Status.Family;
 import javax.ws.rs.core.UriBuilder;
 import javax.ws.rs.core.MediaType;
@@ -747,8 +746,8 @@ public <T> T invokeAPI(String path, String method, List<Pair> queryParams, Objec
 
     ClientResponse response = getAPIResponse(path, method, queryParams, body, headerParams, formParams, accept, contentType, authNames);
 
-    if (response.getStatusInfo().getStatusCode() != Status.OK.getStatusCode()) {
-        throw new ApiException("Error while requesting server, received HTTP code: "+ response.getStatusInfo().getStatusCode() + " / with response Body: " + response.getEntity(String.class));
+    if (response.getStatusInfo().getFamily() != Family.SUCCESSFUL) {
+        throw new ApiException("Error while requesting server, received HTTP code: " + response.getStatusInfo().getStatusCode() + " / with response Body: " + response.getEntity(String.class));
     }
 
     statusCode = response.getStatusInfo().getStatusCode();