private static String getMimeType(Iterable<Resource> resources) {

        // If no resources, just assume application/octet-stream
        Iterator<Resource> resourceIterator = resources.iterator();
        if (!resourceIterator.hasNext())
            return "application/octet-stream";

        // Return mimetype of first resource
        return resourceIterator.next().getMimeType();

    }
Returns the mimetype of the first resource in the given Iterable, or
"application/octet-stream" if no resources are provided.

@param resources
    The resources from which the mimetype should be retrieved.

@return
    The mimetype of the first resource, or "application/octet-stream"
    if no resources were provided.
guacamole/src/main/java/org/apache/guacamole/resource/SequenceResource.java