メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.5250000 42.6125000, 141.5312500 42.6125000, 141.5312500 42.6166667, 141.5250000 42.6166667, 141.5250000 42.6125000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral