Explain: Raise more clear error messages

[exalate-issue-sync]

When there are no explainable models/models with varimp, the explain raises errors like this:

{code:r}
Error: subscript out of bounds
Backtrace:
█

1. ├─global::withWarnings(call_func(test_name, list(), envir = suite$envir))
2. │ └─base::withCallingHandlers(expr, warning = wHandler)
3. ├─base:::call_func(test_name, list(), envir = suite$envir)
4. └─global::explanation_test_automl_binomial_classification()
5. ├─global::expect_ggplot(...)
6. │ └─base::force(gg)
7. └─global::h2o.varimp_heatmap(aml@leaderboard[1:4, ])

8. └─global::.varimp_matrix(object, top_n = top_n)
   

9.   └─global::.process_models_or_automl(...)
   

10.     └─make_models_info(...)
    

11.       └─.models_info$new(...)
    

12.         └─methods::new(def, ...)
    

13.           ├─methods::initialize(value, ...)
    

14.           └─methods::initialize(value, ...)
    

15.             └─.Object$initialize(...)
    

{code}

[h2o-ops-ro]

JIRA Issue Details

Jira Issue: PUBDEV-8357
Assignee: Tomas Fryda
Reporter: Tomas Fryda
State: Resolved
Fix Version: 3.34.0.3
Attachments: N/A
Development PRs: Available

[h2o-ops-ro]

Linked PRs from JIRA

#5797