private void Dispose(bool disposing)
 {
     lock (this) {
         // no if (disposing) pattern to clean up managed objects
         if (m_pItems[0] != IntPtr.Zero)
         {
             External.curl_formfree(m_pItems[0]);
         }
         m_pItems[0] = IntPtr.Zero;
         m_pItems[1] = IntPtr.Zero;
     }
 }