traits are all AbstractTrait

Author: rafaqz

src/types.jl

@@ -1,5 +1,7 @@
+"An AbstractTrait type for all geometries, features and feature collections."
+abstract type AbstractTrait end
 "An AbstractGeometryTrait type for all geometries."
-abstract type AbstractGeometryTrait end
+abstract type AbstractGeometryTrait <: AbstractTrait end
 
 "An AbstractGeometryCollectionTrait type for all geometrycollections."
 abstract type AbstractGeometryCollectionTrait <: AbstractGeometryTrait end
@@ -82,11 +84,11 @@ struct MultiPolygonTrait <: AbstractMultiPolygonTrait end
 
 
 "An AbstractFeatureTrait for all features"
-abstract type AbstractFeatureTrait end
+abstract type AbstractFeatureTrait <: AbstractTrait end
 "A FeatureTrait holds `geometries`, `properties` and an `extent`"
 struct FeatureTrait <: AbstractFeatureTrait end
 
 "An AbstractFeatureCollectionTrait for all feature collections"
-abstract type AbstractFeatureCollectionTrait end
+abstract type AbstractFeatureCollectionTrait <: AbstractTrait end
 "A FeatureCollectionTrait holds objects of `FeatureTrait` and an `extent`"
 struct FeatureCollectionTrait <: AbstractFeatureCollectionTrait end