メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((137.7937500 34.8208334, 137.8000000 34.8208334, 137.8000000 34.8250000, 137.7937500 34.8250000, 137.7937500 34.8208334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral