code: def test_pipeline_builder_merge_one_to_one():
      builder_many_to_one = (
          PipelineBuilder()
          .add_branch("operation_b", "operation_d")
          .join_branches("operation_f")
      )
      builder_one_to_many = (
          PipelineBuilder()
          .add_node("operation_c")
          .add_branch("operation_g", "operation_a")
      )
  
      # merge one final to one initial node
      assert builders_same(
          merge_pipeline_builders(
              builder_many_to_one, builder_one_to_many
          ),
          PipelineBuilder()
          .add_branch("operation_b", "operation_d")
          .join_branches("operation_f")
          .add_node("operation_c")
          .add_branch("operation_g", "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 11 for calling a global function with example usage: test_pipeline_builder_merge_one_to_one() without return types