メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.4125000 35.7875000, 138.4187500 35.7875000, 138.4187500 35.7916667, 138.4125000 35.7916667, 138.4125000 35.7875000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral