メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((137.9437500 36.9208334, 137.9500000 36.9208334, 137.9500000 36.9250000, 137.9437500 36.9250000, 137.9437500 36.9208334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral