メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((143.6000000 42.8208334, 143.6062500 42.8208334, 143.6062500 42.8250000, 143.6000000 42.8250000, 143.6000000 42.8208334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral