MsgHtmlTagNode mhtn3 = (MsgHtmlTagNode) mpn3.getChild(0);
assertEquals("a", mhtn3.getLcTagName());
assertEquals("START_LINK", mhtn3.genBasePlaceholderName());
assertEquals("<a href=\"{$learnMoreUrl}\">", mhtn3.toSourceString());
assertEquals(3, mhtn3.numChildren());
assertEquals("<a href=\"", ((RawTextNode) mhtn3.getChild(0)).getRawText());
assertEquals("$learnMoreUrl", ((PrintNode) mhtn3.getChild(1)).getExprText());
assertEquals("\">", ((RawTextNode) mhtn3.getChild(2)).getRawText());
assertEquals("Learn more", ((RawTextNode) mn0.getChild(4)).getRawText());