メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.8687500 42.8208334, 142.8750000 42.8208334, 142.8750000 42.8250000, 142.8687500 42.8250000, 142.8687500 42.8208334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral