Name
ST_NumInteriorRing — Return the number of interior rings of the first polygon in
			the geometry. Synonym to ST_NumInteriorRings. 
Synopsis
integer ST_NumInteriorRing(geometry  a_polygon);
Description
Return the number of interior rings of the first polygon in
			the geometry. Synonym to ST_NumInteriorRings. The OpenGIS specs are
			ambiguous about the exact function naming, so we provide both
			spellings.
 This method implements the SQL/MM specification. SQL-MM 3: 8.2.5
 This method implements the SQL/MM specification. SQL-MM 3: 8.2.5