Is object of class "kernelshap"?
is.kernelshap(object)TRUE if object is of class "kernelshap", and FALSE otherwise.
fit <- lm(Sepal.Length ~ ., data = iris)
s <- kernelshap(fit, iris[1:2, -1], bg_X = iris[, -1])
#> Exact Kernel SHAP values
#> 
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is.kernelshap(s)
#> [1] TRUE
is.kernelshap("a")
#> [1] FALSE