private static final void writeAttr(Writer out, String name, String value) throws IOException {
out.write(' ');
out.write(name);
out.write("=\"");
out.write(XMLs.encodeAttribute(value));
out.write('"');
}
/** Appends an attribute to the string buffer, if <code>attrValue</code> is not null. */
protected static final void append(StringBuffer sb, String attrName, String attrValue) {
if (attrValue != null)
sb.append(' ')
.append(attrName)
.append("=\"")
.append(XMLs.encodeAttribute(attrValue))
.append('"');
// it might contain " or other special characters
}