メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((137.9187500 36.0708334, 137.9250000 36.0708334, 137.9250000 36.0750000, 137.9187500 36.0750000, 137.9187500 36.0708334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral