{
  "name": "collect",
  "type": "function",
  "groups": ["Aggregates"],
  "description": "Returns the multipart geometry of aggregated geometries from an expression",
  "arguments": [{
    "arg": "expression",
    "description": "geometry expression to aggregate"
  }, {
    "arg": "group_by",
    "optional": true,
    "description": "optional expression to use to group aggregate calculations"
  }, {
    "arg": "filter",
    "optional": true,
    "description": "optional expression to use to filter features used to calculate aggregate"
  }],
  "examples": [{
    "expression": "collect( @geometry )",
    "returns": "multipart geometry of aggregated geometries"
  }, {
    "expression": "collect( centroid(@geometry), group_by:=\"region\", filter:= \"use\" = 'civilian' )",
    "returns": "aggregated centroids of the civilian features based on their region value"
  }],
  "tags": ["aggregated", "multipart"]
}