class_docstr: Abstract base class for population-based search methods.
  
  Examples include: genetic algorithm, particle swarm optimization
class_docstr_tok: ["Abstract","base","class","for","population-based","search","methods",".","Examples","include",":","genetic","algorithm",",","particle","swarm","optimization"]
docstr: Perturb `pop_member` in-place.
  
  Must be overridden by specific population-based method
  Args:
      pop_member (PopulationMember): Population member to perturb            original_result (GoalFunctionResult): Result for original text. Often needed for constraint checking.
  Returns
      `True` if perturbation occured. `False` if not.
docstr_tok: ["Perturb","`","pop_member","`","in-place",".","Must","be","overridden","by","specific","population-based","method","Args",":","pop_member","(","PopulationMember",")",":","Population","member","to","perturb","original_result","(","GoalFunctionResult",")",":","Result","for","original","text",".","Often","needed","for","constraint","checking",".","Returns","`","True","`","if","perturbation","occured",".","`","False","`","if","not","."]
code: def _perturb(self, pop_member, original_result, **kwargs):
      """Perturb `pop_member` in-place.
  
          Must be overridden by specific population-based method
          Args:
              pop_member (PopulationMember): Population member to perturb\
              original_result (GoalFunctionResult): Result for original text. Often needed for constraint checking.
          Returns
              `True` if perturbation occured. `False` if not.
          """
      raise NotImplementedError()
  
file_path: TextAttack/textattack/search_methods/population_based_search.py
imports: from abc import ABC, abstractmethod
  from textattack.search_methods import SearchMethod
label_desc: Use image node_id 2 for calling the PopulationBasedSearch obj's underlying member method code with example usage: obj._perturb(pop_member, original_result) without return types