{
  "name": "num_rings",
  "type": "function",
  "groups": ["GeometryGroup"],
  "description": "Returns the number of rings (including exterior rings) in a polygon or geometry collection, or NULL if the input geometry is not a polygon or collection.",
  "arguments": [{
    "arg": "geometry",
    "description": "input geometry"
  }],
  "examples": [{
    "expression": "num_rings(geom_from_wkt('POLYGON((-1 -1, 4 0, 4 2, 0 2, -1 -1),(-0.1 -0.1, 0.4 0, 0.4 0.2, 0 0.2, -0.1 -0.1))'))",
    "returns": "2"
  }],
  "tags": ["rings", "holes", "polygon", "collection", "exterior", "including"]
}