メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((137.8187500 34.8875000, 137.8250000 34.8875000, 137.8250000 34.8916667, 137.8187500 34.8916667, 137.8187500 34.8875000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral