メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((137.7937500 35.5208334, 137.8000000 35.5208334, 137.8000000 35.5250000, 137.7937500 35.5250000, 137.7937500 35.5208334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral