メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.0750000 38.8166667, 141.0812500 38.8166667, 141.0812500 38.8208334, 141.0750000 38.8208334, 141.0750000 38.8166667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral