def outputs(self):
"""
A dictionary of all output ops as "name:op" pairs
Notes:
Outputs are defined as matching 1 of 2 criteria:
1. Ops in the subgraph that aren't depended on by any other ops in the subgraph
2. Not a variable or placeholder op
"""
op_args = OrderedSet()
ops = OrderedSet()
for op in self:
if isinstance(op, ng.AssignableTensorOp):
continue
ops.add(op)
for arg_op in op.args + tuple(op.control_deps):
op_args.add(arg_op)
return OrderedDict((op.name, op) for op in ops.difference(op_args))
