メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((137.6187500 34.6875000, 137.6250000 34.6875000, 137.6250000 34.6916667, 137.6187500 34.6916667, 137.6187500 34.6875000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral