A Feature isn't a standard class in the SFS.

It represents an arbirtray object with a set of non-spatial properties and one dedicated spatial property called geometry.

It is is mainly used to deserialized GeoJSON objects with type: "Feature".

abstract class Feature {
 /**
  * Creates a feature with a specific [geometry] and an (optional) set
  * of properties.
  *
  * [geometry] must not be null, otherwise throws an [ArgumentError].
  *
  * [properties] are optional, and if present, they can be null or empty.
  */
 factory Feature(Geometry geometry, [Map<String, dynamic> properties=null]) {
   return new _FeatureImpl(geometry,properties);
 }

 Geometry get geometry;
 Map<String, dynamic> get properties;
}