メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.3500000 31.6125000, 131.3562500 31.6125000, 131.3562500 31.6166667, 131.3500000 31.6166667, 131.3500000 31.6125000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral