code: def get_pipelines():
      one_node_pipeline = (
          PipelineBuilder().add_sequence("logit").build()
      )
      linear_pipeline = (
          PipelineBuilder()
          .add_sequence("logit", "logit", "logit")
          .build()
      )
      branching_structure = (
          PipelineBuilder()
          .add_node("operation_a")
          .add_branch("operation_a", "operation_f")
          .join_branches("operation_f")
          .build()
      )
      branching_structure2 = (
          PipelineBuilder()
          .add_node("operation_a")
          .add_branch("operation_b", "operation_c")
          .grow_branches("operation_d", None)
          .join_branches("operation_f")
          .add_node("operation_a")
          .build()
      )
      node_a = PipelineNode("logit")
      node_b = PipelineNode("logit", nodes_from=[node_a])
      node_c = PipelineNode("logit", nodes_from=[node_b, node_a])
      skip_connection_structure = Pipeline(node_c)
  
      return [
          one_node_pipeline,
          linear_pipeline,
          branching_structure,
          branching_structure2,
          skip_connection_structure,
      ]
  
imports: from copy import deepcopy
  from random import choice
  import numpy
  import pytest
  from golem.core.dag.graph_node import GraphNode
  from golem.core.dag.graph_verifier import GraphVerifier
  from golem.core.dag.verification_rules import DEFAULT_DAG_RULES
  from golem.core.optimisers.graph import OptNode
  from fedot.core.operations.operation import Operation
  from fedot.core.pipelines.adapters import PipelineAdapter
  from fedot.core.pipelines.node import PipelineNode
  from fedot.core.pipelines.pipeline import Pipeline
  from fedot.core.pipelines.pipeline_builder import PipelineBuilder
  from test.unit.dag.test_graph_utils import find_first
  from test.unit.tasks.test_regression import get_synthetic_regression_data
label_desc: Use image node_id 1 for calling a global function with example usage: get_pipelines() and returns: list