メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((137.7937500 35.4916667, 137.8000000 35.4916667, 137.8000000 35.4958334, 137.7937500 35.4958334, 137.7937500 35.4916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral