メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.7125000 44.0750000, 141.7187500 44.0750000, 141.7187500 44.0791667, 141.7125000 44.0791667, 141.7125000 44.0750000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral