メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.8000000 42.7500000, 141.8062500 42.7500000, 141.8062500 42.7541667, 141.8000000 42.7541667, 141.8000000 42.7500000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral