code: def test_pipeline_builder_merge_duplicate():
      builder_one_to_one = PipelineBuilder().add_sequence(
          "operation_a", "operation_f"
      )
  
      # duplicate builder
      assert builders_same(
          merge_pipeline_builders(
              builder_one_to_one, builder_one_to_one
          ),
          PipelineBuilder().add_sequence(
              "operation_a", "operation_f", "operation_a", "operation_f"
          ),
      )
      # check that builder state is preserved after merge and can be reused
      assert graphs_same(
          builder_one_to_one.build(),
          Pipeline(
              PipelineNode(
                  "operation_f",
                  nodes_from=[PipelineNode("operation_a")],
              )
          ),
      )
  
imports: from copy import copy
  from fedot.core.pipelines.pipeline_builder import PipelineBuilder, merge_pipeline_builders
  from fedot.core.pipelines.node import PipelineNode
  from fedot.core.pipelines.pipeline import Pipeline
  from test.unit.dag.test_graph_utils import graphs_same
label_desc: Use image node_id 10 for calling a global function with example usage: test_pipeline_builder_merge_duplicate() without return types