メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.7125000 42.6500000, 141.7187500 42.6500000, 141.7187500 42.6541667, 141.7125000 42.6541667, 141.7125000 42.6500000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral