Signature name as a string. If omitted, it is interpreted as 'default'
and is the signature used when Module.callsignature is not
specified.
inputs
A dict from input name to Tensor or composite tensor (such as
SparseTensor or RaggedTensor) to feed when applying the signature. If a
single tensor is passed, it is interpreted as a dict with a single
'default' entry.
outputs
A dict from output name to Tensor or composite tensor (such as
SparseTensor or RaggedTensor) to return from applying the signature. If a
single tensor is passed, it is interpreted as a dict with a single
'default' entry.