tf.OpError.__init__(node_def, op, message, error_code)
Creates a new OpError indicating that a particular op failed.
Args:
node_def: The node_def_pb2.NodeDef proto representing the op that failed, if known; otherwise None.
op: The ops.Operation that failed, if known; otherwise None.
message: The message string describing the failure.
error_code: The error_codes_pb2.Code describing the error.