メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.4500000 43.7250000, 142.4562500 43.7250000, 142.4562500 43.7291667, 142.4500000 43.7291667, 142.4500000 43.7250000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral