code: def nodes():
      primary_node = OptNode(content={"name": "pca"})
      intermediate_node = OptNode(
          content={"name": "dt"}, nodes_from=[primary_node]
      )
      secondary_node = OptNode(
          content={"name": "logit"}, nodes_from=[intermediate_node]
      )
      return primary_node, intermediate_node, secondary_node
  
file_path: FEDOT/test/unit/pipelines/test_pipeline_node_factory.py
imports: import pytest
  from fedot.core.pipelines.pipeline_composer_requirements import PipelineComposerRequirements
  from golem.core.optimisers.graph import OptNode
  from fedot.core.pipelines.pipeline_advisor import PipelineChangeAdvisor
  from fedot.core.pipelines.pipeline_node_factory import PipelineOptNodeFactory
  from fedot.core.repository.tasks import Task, TaskTypesEnum
label_desc: Use image node_id 1 for calling a global function with example usage: nodes() and returns: primary_node,  intermediate_node,  secondary_node