builder = new UriBuilderImpl();
builder.queryParam("{qname1}", "{qvalue1}");
uriString = builder.build("q1", "a1").toString();
assertEquals("?q1=a1", uriString);
builder.queryParam("{qname2}", "{qvalue1}");
uriString = builder.build("q1", "a1", "q2").toString();
assertEquals("?q1=a1&q2=a1", uriString);
builder.replaceQueryParam("{qname2}", "b1", "b2");
uriString = builder.build("q1", "a1", "q2").toString();