{
  "function": "buffer",
  "description": "Returns a geometry that represents all points whose distance from this geometry is less than or equal to distance. Calculations are in the Spatial Reference System of this geometry.",
  "arguments": [ {"arg":"geom","description":"a geometry"},
                 {"arg":"distance","description":"buffer distance in layer units"}],
  "examples": [ { "expression":"buffer($geometry, 10.5)", "returns":"polygon of $geometry buffered by 10.5 units"}]
}