メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.4500000 38.7875000, 141.4562500 38.7875000, 141.4562500 38.7916667, 141.4500000 38.7916667, 141.4500000 38.7875000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral