<https://researchdatapod.com/how-to-solve-python-attributeerror-str-object-has-no-attribute-close/#breadcrumb>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://researchdatapod.com/how-to-solve-python-attributeerror-str-object-has-no-attribute-close/>