メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.761851979709 43.1925556387229, 141.761794356974 43.1926099672312, 141.760895614411 43.1921309928515, 141.762266196845 43.1907003284375, 141.763163753876 43.1911639552146, 141.762608534522 43.1917569157684, 141.761851979709 43.1925556387229)) ^^http://www.opengis.net/ont/geosparql#wktLiteral