@type t() :: %Nx.Defn.Graph.Stage{
  arguments: [%{source: {reference() | nil, non_neg_integer()}}],
  expr: %Nx.Defn.Expr{},
  id: reference()
}

A stage in the graph splitter.

• :arguments: a list of maps that point to the source from which to fetch the corresponding value for the given argument.
• :expr: the expression that represents the computation for the Stage.
• :id: the unique id for the Stage.