tokens: The schemaLocation does not matter but your input sample has the default namespace declaration xmlns = " http://www.w3schools.com " on the root element which puts all elements in that namespace .
ner_tags: O B-Variable O O O O O O O O O O O O B-Code_Block I-Code_Block I-Code_Block I-Code_Block I-Code_Block O O O O O O O O O O O O