node and associated metadata.}]>:$key,
    Res<TF_BoolTensor, [{If the `must_compile` attr is false the _XlaCompile op
can decide not to compile the clusters based on some profitability
heuristics.  In that case `compilation_successful` is false if _XlaCompile
chose not to compile the cluster.  If the `must_compile` attr is true then
_XlaCompile always attempts to compile the cluster and