// * int is used as an index into arrays.
// * Deletion functions are safe to call on nullptr.
//
// Questions left to address:
// * Might at some point need a way for callers to provide their own Env.
// * Maybe add TF_TensorShape that encapsulates dimension info.
//
// Design decisions made:
// * Backing store for tensor memory has an associated deallocation

/// the struct pointer (e.g., when a file type is not supported).
///
/// DEFAULT IMPLEMENTATIONS: Some operations have default implementations that
/// TensorFlow uses in case the plugin doesn't supply its own version. An
/// operation `foo` might have a default implementation which uses `bar` and
/// `foobar`. If the plugin supplies `bar` and `foobar`, TensorFlow can use the
/// default implementation of `foo`.
///