STRU and exception tasks accepted; G6 cascade fix, exception class mutants, RTTI unit notes

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

tasks_gen/train/G1904/task.json

@@ -0,0 +1,50 @@
+{
+  "id": "G1904",
+  "category": "D",
+  "object_type": "CLAS",
+  "difficulty": 2,
+  "release_target": "v816",
+  "expected_outcome": "implement",
+  "budget": {
+    "max_tool_calls": 60,
+    "max_activations": 15
+  },
+  "seed": [
+    {
+      "type": "INTF",
+      "name": "{{P}}IF_ISSUE_ERROR_INFO",
+      "file": "seed/if_issue_error_info.intf.abap",
+      "description": "Contract interface with the case type and the getters of the issue error"
+    }
+  ],
+  "contract": [
+    {
+      "type": "CLAS",
+      "name": "{{P}}CX_ISSUE_ERROR",
+      "implements": "{{P}}IF_ISSUE_ERROR_INFO"
+    }
+  ],
+  "out_of_scope": [
+    "{{P}}IF_ISSUE_ERROR_INFO"
+  ],
+  "hidden_tests": [
+    {
+      "type": "CLAS",
+      "name": "{{P}}D02_HIDDEN",
+      "file": "hidden/d02_hidden.clas.abap",
+      "description": "D02 hidden tests for the issue error exception class"
+    }
+  ],
+  "reference": [
+    {
+      "type": "CLAS",
+      "name": "{{P}}CX_ISSUE_ERROR",
+      "file": "reference/cx_issue_error.clas.abap",
+      "description": "Exception class with case constants, context data and a redefined GET_TEXT",
+      "testclasses_file": "reference/cx_issue_error.testclasses.abap"
+    }
+  ],
+  "craft_checks": [
+    "method_length"
+  ]
+}