https://docs.oracle.com/javase/jp/11/docs/api/jdk.xml.dom/org/w3c/dom/xpath/XPathNamespace.html
XPathNamespace (Java SE 11 & JDK 11 )
java sejdk
https://xalan.apache.org/old/xalan-j/apidocs/org/w3c/dom/xpath/class-use/XPathNamespace.html
Xalan-Java 2.7.1: Uses of Interface org.w3c.dom.xpath.XPathNamespace