code: def _process_inputs(schema, spec, inputs, operator_name):
      """Process inputs: validate, add to spec and return the list of DataNodes that need to be kept
      alive for the graph to exist.
  
      Returns
      -------
      List
          the list of DataNodes representing inputs (there may be conversions)
      """
      if (
          len(inputs) < schema.MinNumInput()
          or len(inputs) > schema.MaxNumInput()
      ):
          raise ValueError(
              f"Operator {operator_name} expects "
              f"from {schema.MinNumInput()} to {schema.MaxNumInput()} inputs, "
              f"but received {len(inputs)}."
          )
      if not inputs:
          return []
      for inp in inputs:
          if not isinstance(inp, _DataNode):
              raise TypeError(
                  f"Expected inputs of type `DataNode`. Received input of type '{inp}'."
              )
          spec.AddInput(inp.name, inp.device)
      return list(inputs)
  
imports: import sys
  import threading
  import tree
  import warnings
  from itertools import count
  import nvidia.dali.python_function_plugin
  from nvidia.dali import backend
  from nvidia.dali import fn
  from nvidia.dali import internal
  from nvidia.dali.data_node import DataNode
  from nvidia.dali.pipeline import Pipeline
  from nvidia.dali.types import _type_name_convert_to_string, _type_convert_value, _default_converter, _vector_element_type, ScalarConstant, Constant
  from nvidia.dali import _conditionals
  from nvidia.dali.ops import _registry, _names, _docs, _operator_utils
  from nvidia.dali.ops._registry import cpu_ops, mixed_ops, gpu_ops, register_cpu_op, register_gpu_op
  from nvidia.dali.ops._names import _op_name, _process_op_name, _schema_name
  from nvidia.dali.ops._operator_utils import _build_input_sets, _repack_output_sets
  from nvidia.dali.external_source import ExternalSource
  from nvidia.dali.ops._operators.python_function import PythonFunctionBase, PythonFunction, DLTensorPythonFunction, _dlpack_to_array, _dlpack_from_array
  from nvidia.dali.ops._operators.compose import Compose
  from nvidia.dali.ops._operators.math import _arithm_op, _group_inputs, _generate_input_desc
label_desc: Use image node_id 9 for calling a global function with example usage: _process_inputs(schema, spec, inputs, operator_name) and returns: list, list