メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((137.0500000 36.7750000, 137.0562500 36.7750000, 137.0562500 36.7791667, 137.0500000 36.7791667, 137.0500000 36.7750000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral