diff --git a/16fa10433ca040b01f6216b9ef95ec97de54eb0e b/16fa10433ca040b01f6216b9ef95ec97de54eb0e
index 3a737f8..ff251fc 100644
--- a/16fa10433ca040b01f6216b9ef95ec97de54eb0e
+++ b/16fa10433ca040b01f6216b9ef95ec97de54eb0e
@@ -23,6 +23,30 @@
       "serverId": "4a232e18-c5a9-48ee-94c0-e04e7cca6543",
       "unresolved": true
     },
+    {
+      "key": {
+        "uuid": "7125e3bd_63e9daab",
+        "filename": "charms_ceph/utils.py",
+        "patchSetId": 5
+      },
+      "lineNbr": 520,
+      "author": {
+        "id": 32363
+      },
+      "writtenOn": "2021-06-28T17:26:54Z",
+      "side": 1,
+      "message": "Done",
+      "parentUuid": "af4c92f9_90d9bd12",
+      "range": {
+        "startLine": 509,
+        "startChar": 0,
+        "endLine": 520,
+        "endChar": 30
+      },
+      "revId": "16fa10433ca040b01f6216b9ef95ec97de54eb0e",
+      "serverId": "4a232e18-c5a9-48ee-94c0-e04e7cca6543",
+      "unresolved": false
+    },
     {
       "key": {
         "uuid": "3c75a2fe_c629a5cd",
@@ -46,6 +70,30 @@
       "serverId": "4a232e18-c5a9-48ee-94c0-e04e7cca6543",
       "unresolved": true
     },
+    {
+      "key": {
+        "uuid": "85491094_764e0e47",
+        "filename": "charms_ceph/utils.py",
+        "patchSetId": 5
+      },
+      "lineNbr": 578,
+      "author": {
+        "id": 32363
+      },
+      "writtenOn": "2021-06-28T17:26:54Z",
+      "side": 1,
+      "message": "Ack",
+      "parentUuid": "3c75a2fe_c629a5cd",
+      "range": {
+        "startLine": 577,
+        "startChar": 0,
+        "endLine": 578,
+        "endChar": 47
+      },
+      "revId": "16fa10433ca040b01f6216b9ef95ec97de54eb0e",
+      "serverId": "4a232e18-c5a9-48ee-94c0-e04e7cca6543",
+      "unresolved": false
+    },
     {
       "key": {
         "uuid": "47c7b38e_834e872c",
@@ -63,6 +111,24 @@
       "serverId": "4a232e18-c5a9-48ee-94c0-e04e7cca6543",
       "unresolved": true
     },
+    {
+      "key": {
+        "uuid": "eb95dac2_d6326910",
+        "filename": "charms_ceph/utils.py",
+        "patchSetId": 5
+      },
+      "lineNbr": 589,
+      "author": {
+        "id": 32363
+      },
+      "writtenOn": "2021-06-28T17:26:54Z",
+      "side": 1,
+      "message": "You\u0027re right, it should. Actually it\u0027s returning only grand-(grand-(...))-children and stops at the desired type or finds the youngest descendant (lowest in CRUSH hierarchy).",
+      "parentUuid": "47c7b38e_834e872c",
+      "revId": "16fa10433ca040b01f6216b9ef95ec97de54eb0e",
+      "serverId": "4a232e18-c5a9-48ee-94c0-e04e7cca6543",
+      "unresolved": true
+    },
     {
       "key": {
         "uuid": "76f03583_f5e0ed18",
@@ -86,6 +152,30 @@
       "serverId": "4a232e18-c5a9-48ee-94c0-e04e7cca6543",
       "unresolved": true
     },
+    {
+      "key": {
+        "uuid": "5924e21c_60aa4e0f",
+        "filename": "charms_ceph/utils.py",
+        "patchSetId": 5
+      },
+      "lineNbr": 617,
+      "author": {
+        "id": 32363
+      },
+      "writtenOn": "2021-06-28T17:26:54Z",
+      "side": 1,
+      "message": "You\u0027re right 💯, this really good example of why the `_load_ceph_osd_tree` function is just confusing. When I wrote this docstring, I only looked at json.",
+      "parentUuid": "76f03583_f5e0ed18",
+      "range": {
+        "startLine": 617,
+        "startChar": 18,
+        "endLine": 617,
+        "endChar": 38
+      },
+      "revId": "16fa10433ca040b01f6216b9ef95ec97de54eb0e",
+      "serverId": "4a232e18-c5a9-48ee-94c0-e04e7cca6543",
+      "unresolved": true
+    },
     {
       "key": {
         "uuid": "54b9c32a_7fd7eee3",
@@ -103,6 +193,24 @@
       "serverId": "4a232e18-c5a9-48ee-94c0-e04e7cca6543",
       "unresolved": true
     },
+    {
+      "key": {
+        "uuid": "e365f8e0_0f2e1c68",
+        "filename": "charms_ceph/utils.py",
+        "patchSetId": 5
+      },
+      "lineNbr": 625,
+      "author": {
+        "id": 32363
+      },
+      "writtenOn": "2021-06-28T17:26:54Z",
+      "side": 1,
+      "message": "Done",
+      "parentUuid": "54b9c32a_7fd7eee3",
+      "revId": "16fa10433ca040b01f6216b9ef95ec97de54eb0e",
+      "serverId": "4a232e18-c5a9-48ee-94c0-e04e7cca6543",
+      "unresolved": false
+    },
     {
       "key": {
         "uuid": "8c22b177_2e6cffcb",
@@ -120,6 +228,24 @@
       "serverId": "4a232e18-c5a9-48ee-94c0-e04e7cca6543",
       "unresolved": true
     },
+    {
+      "key": {
+        "uuid": "1da1c6db_8b039332",
+        "filename": "charms_ceph/utils.py",
+        "patchSetId": 5
+      },
+      "lineNbr": 626,
+      "author": {
+        "id": 32363
+      },
+      "writtenOn": "2021-06-28T17:26:54Z",
+      "side": 1,
+      "message": "Done",
+      "parentUuid": "8c22b177_2e6cffcb",
+      "revId": "16fa10433ca040b01f6216b9ef95ec97de54eb0e",
+      "serverId": "4a232e18-c5a9-48ee-94c0-e04e7cca6543",
+      "unresolved": false
+    },
     {
       "key": {
         "uuid": "9f2da9d5_82c3d518",
@@ -137,6 +263,24 @@
       "serverId": "4a232e18-c5a9-48ee-94c0-e04e7cca6543",
       "unresolved": true
     },
+    {
+      "key": {
+        "uuid": "e67d3e12_e4998c4c",
+        "filename": "charms_ceph/utils.py",
+        "patchSetId": 5
+      },
+      "lineNbr": 645,
+      "author": {
+        "id": 32363
+      },
+      "writtenOn": "2021-06-28T17:26:54Z",
+      "side": 1,
+      "message": "Yes, you are right. I mixed both patterns and I will use the second one as you suggested, because I don\u0027t see any simple solution how the aggregate returns from recursion.",
+      "parentUuid": "9f2da9d5_82c3d518",
+      "revId": "16fa10433ca040b01f6216b9ef95ec97de54eb0e",
+      "serverId": "4a232e18-c5a9-48ee-94c0-e04e7cca6543",
+      "unresolved": true
+    },
     {
       "key": {
         "uuid": "ae833a06_e7bf0cbc",
@@ -160,6 +304,30 @@
       "serverId": "4a232e18-c5a9-48ee-94c0-e04e7cca6543",
       "unresolved": true
     },
+    {
+      "key": {
+        "uuid": "e292d516_022e5f1a",
+        "filename": "charms_ceph/utils.py",
+        "patchSetId": 5
+      },
+      "lineNbr": 653,
+      "author": {
+        "id": 32363
+      },
+      "writtenOn": "2021-06-28T17:26:54Z",
+      "side": 1,
+      "message": "Done",
+      "parentUuid": "ae833a06_e7bf0cbc",
+      "range": {
+        "startLine": 653,
+        "startChar": 14,
+        "endLine": 653,
+        "endChar": 19
+      },
+      "revId": "16fa10433ca040b01f6216b9ef95ec97de54eb0e",
+      "serverId": "4a232e18-c5a9-48ee-94c0-e04e7cca6543",
+      "unresolved": false
+    },
     {
       "key": {
         "uuid": "1a8fa696_b77162db",
@@ -205,6 +373,30 @@
       "revId": "16fa10433ca040b01f6216b9ef95ec97de54eb0e",
       "serverId": "4a232e18-c5a9-48ee-94c0-e04e7cca6543",
       "unresolved": true
+    },
+    {
+      "key": {
+        "uuid": "cf6a58c7_b2156aab",
+        "filename": "charms_ceph/utils.py",
+        "patchSetId": 5
+      },
+      "lineNbr": 666,
+      "author": {
+        "id": 32363
+      },
+      "writtenOn": "2021-06-28T17:26:54Z",
+      "side": 1,
+      "message": "* Yes, that\u0027s correct\n* No, a leaf can only be on one tree\n* Yes, that\u0027s correct\n* Yes, that\u0027s correct (I think)\n* Yes, that\u0027s correct\n\nI was not able to tested [1] it your suggestion, because `descendant_attribute_dicts` could be [], [[{\u0027osd\u0027: \u0027osd.1\u0027}]] or [[None]].\n\n---\n[1]: https://pastebin.canonical.com/p/GjpT42BQg3/",
+      "parentUuid": "e2b53e73_893c13a4",
+      "range": {
+        "startLine": 664,
+        "startChar": 0,
+        "endLine": 666,
+        "endChar": 79
+      },
+      "revId": "16fa10433ca040b01f6216b9ef95ec97de54eb0e",
+      "serverId": "4a232e18-c5a9-48ee-94c0-e04e7cca6543",
+      "unresolved": true
     }
   ]
 }
\ No newline at end of file
diff --git a/9b34af1aea048f72cb1bd840aec19a5068a83009 b/9b34af1aea048f72cb1bd840aec19a5068a83009
index 321851d..92911f2 100644
--- a/9b34af1aea048f72cb1bd840aec19a5068a83009
+++ b/9b34af1aea048f72cb1bd840aec19a5068a83009
@@ -23,6 +23,30 @@
       "serverId": "4a232e18-c5a9-48ee-94c0-e04e7cca6543",
       "unresolved": true
     },
+    {
+      "key": {
+        "uuid": "a9877583_fe1c526d",
+        "filename": "charms_ceph/utils.py",
+        "patchSetId": 4
+      },
+      "lineNbr": 506,
+      "author": {
+        "id": 32363
+      },
+      "writtenOn": "2021-06-28T17:26:54Z",
+      "side": 1,
+      "message": "You are right, string aren\u0027t mutable. However, I think this way it will handle a better situation when someone pass a parameter like None. e.g CrushLocation(..., osd\u003dNone)\n\nThe fair point is that it is not used in any other function, only in get_osd_tree. [1] \u003d\u003e It can be changed without any harm and I will change it.\n---\n[1]: https://codesearch.opendev.org/?q\u003dCrushLocation\u0026i\u003dnope\u0026files\u003d\u0026excludeFiles\u003d\u0026repos\u003d",
+      "parentUuid": "9a1d8040_b3d4daeb",
+      "range": {
+        "startLine": 504,
+        "startChar": 0,
+        "endLine": 506,
+        "endChar": 69
+      },
+      "revId": "9b34af1aea048f72cb1bd840aec19a5068a83009",
+      "serverId": "4a232e18-c5a9-48ee-94c0-e04e7cca6543",
+      "unresolved": true
+    },
     {
       "key": {
         "uuid": "34b08069_38a4e1fb",