code: public @Nonnull Stream<String> allValue(String xpath) {
          return select(xpath).map(XQuery::allText);
      }
docs: Selects values based on the XPath expression that is applied to the tree
  represented by this {@link XQuery}. In contrast to {@link #value(String)}, this
  method reads the element texts recursively, using {@link #allText()}.
  
  @param xpath
  XPath expression
  @return Stream of strings containing the node values