private final void append(List<? super NameValuePair> l,final String k,final String v){
  if (v != null)   l.add(new NameValuePair(k,v));
}

private final void append ( List < ? super NameValuePair > l , final String k , final String v ) { if ( v != null ) l . add ( new NameValuePair ( k , v ) ) ; }
appends a namevaluepair of k / v to l if v is non - null .
