class_docstr: Abstracts task-specific pipeline assumptions. 
class_docstr_tok: ["Abstracts","task-specific","pipeline","assumptions","."]
docstr: Returns default PipelineBuilder for case when primary alternatives are not valid.
  Have access for OperationsFilter for sampling available operations.
docstr_tok: ["Returns","default","PipelineBuilder","for","case","when","primary","alternatives","are","not","valid",".","Have","access","for","OperationsFilter","for","sampling","available","operations","."]
code: def fallback_builder(
      self, operations_filter: OperationsFilter
  ) -> PipelineBuilder:
      """
      Returns default PipelineBuilder for case when primary alternatives are not valid.
      Have access for OperationsFilter for sampling available operations.
      """
      raise AbstractMethodNotImplementError
  
imports: from abc import abstractmethod
  from typing import List
  from fedot.api.api_utils.assumptions.operations_filter import OperationsFilter
  from fedot.core.pipelines.pipeline_builder import PipelineBuilder
  from fedot.core.repository.operation_types_repository import OperationTypesRepository
  from fedot.core.repository.tasks import Task, TaskTypesEnum
  from fedot.utilities.custom_errors import AbstractMethodNotImplementError
label_desc: Use image node_id 5 for calling the TaskAssumptions obj's underlying member method code with example usage: obj.fallback_builder(operations_filter) without return types