This symbol is a type alias.
Source:
NestedTensorOrArray = Union[
tensorflow.python.framework.tensor.Tensor,
tensorflow.python.framework.sparse_tensor.SparseTensor,
tensorflow.python.ops.ragged.ragged_tensor.RaggedTensor,
tensorflow.python.framework.ops.EagerTensor,
Iterable[ForwardRef('NestedTensor')],
Mapping[str, ForwardRef('NestedTensor')],
numpy.ndarray,
int,
float,
str,
bool,
Iterable[ForwardRef('NestedArray')],
Mapping[str, ForwardRef('NestedArray')]
]