@Nullable
    public String getMimeFileExtension() {
        ensureMimeInformation();
        return mimeInformation.second;
    }
Check if the URL represents a file on the local file system.

@return <tt>true</tt> if the URL scheme is <tt>file</tt>, <tt>false</tt> otherwise
main/src/main/java/cgeo/geocaching/models/Image.java