メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((137.7125000 35.7875000, 137.7187500 35.7875000, 137.7187500 35.7916667, 137.7125000 35.7916667, 137.7125000 35.7875000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral