🚧 nested sample definitions

This gets rid of the need to manually calculate weight interaction.
Implementation may be trickier.

subsampling/asia_2m.yaml

@@ -1,78 +1,66 @@
 size: 4375
 samples:
-  asia_early:
-    group_by:
-    - division
-    - year
-    - month
-    weight: 12
-    max_date: 2M
-    exclude:
-    - region!=Asia
-    - country=China
-    - country=India
-  china_early:
-    group_by:
-    - division
-    - year
-    - month
-    weight: 8
+  early:
+    weight: 1
     max_date: 2M
-    exclude:
-    - country!=China
-  india_early:
     group_by:
-    - division
-    - year
     - month
-    weight: 8
-    max_date: 2M
-    exclude:
-    - country!=India
-  context_early:
-    group_by:
-    - country
-    - year
-    - month
-    weight: 7
-    max_date: 2M
-    exclude:
-    - region=Asia
-  asia_recent:
-    group_by:
-    - division
-    - year
-    - month
-    weight: 48
+    samples:
+      asia:
+        group_by:
+        - division
+        weight: 12
+        exclude:
+        - region!=Asia
+        - country=China
+        - country=India
+      china:
+        group_by:
+        - division
+        weight: 8
+        exclude:
+        - country!=China
+      india:
+        group_by:
+        - division
+        weight: 8
+        exclude:
+        - country!=India
+      context:
+        group_by:
+        - country
+        weight: 7
+        exclude:
+        - region=Asia
+  recent:
+    weight: 4
     min_date: 2M
-    exclude:
-    - region!=Asia
-    - country=China
-    - country=India
-  china_recent:
     group_by:
-    - division
-    - year
-    - month
-    weight: 32
-    min_date: 2M
-    exclude:
-    - country!=China
-  india_recent:
-    group_by:
-    - division
-    - year
-    - month
-    weight: 32
-    min_date: 2M
-    exclude:
-    - country!=India
-  context_recent:
-    group_by:
-    - country
-    - year
-    - month
-    weight: 28
-    min_date: 2M
-    exclude:
-    - region=Asia
+    - week
+    samples:
+      asia:
+        group_by:
+        - division
+        weight: 12
+        exclude:
+        - region!=Asia
+        - country=China
+        - country=India
+      china:
+        group_by:
+        - division
+        weight: 8
+        exclude:
+        - country!=China
+      india:
+        group_by:
+        - division
+        weight: 8
+        exclude:
+        - country!=India
+      context:
+        group_by:
+        - country
+        weight: 7
+        exclude:
+        - region=Asia