メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.0500000 42.7708334, 141.0562500 42.7708334, 141.0562500 42.7750000, 141.0500000 42.7750000, 141.0500000 42.7708334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral