class_docstr: An RRA class, inherited from Optimizer.
  
  This is the designed class to define RRA-related
  variables and methods.
  
  References:
      F. Merrikh-Bayat.
      The runner-root algorithm: A metaheuristic for solving unimodal and
      multimodal optimization problems inspired by runners and roots of plants in nature.
      Applied Soft Computing (2015).
class_docstr_tok: ["An","RRA","class",",","inherited","from","Optimizer",".","This","is","the","designed","class","to","define","RRA-related","variables","and","methods",".","References",":","F.","Merrikh-Bayat",".","The","runner-root","algorithm",":","A","metaheuristic","for","solving","unimodal","and","multimodal","optimization","problems","inspired","by","runners","and","roots","of","plants","in","nature",".","Applied","Soft","Computing","(","2015",")","."]
docstr: Previous best fitness value.
docstr_tok: ["Previous","best","fitness","value","."]
code: def last_best_fit(self) -> float:
      """Previous best fitness value."""
  
      return self._last_best_fit
  
imports: import copy
  from typing import Any, Dict, List, Optional
  import numpy
  import opytimizer.math.distribution
  import opytimizer.math.random
  import opytimizer.utils.constant
  import opytimizer.utils.exception
  from opytimizer.core import Optimizer
  from opytimizer.core.agent import Agent
  from opytimizer.core.function import Function
  from opytimizer.core.space import Space
  from opytimizer.utils import logging
label_desc: Use image node_id 12 for calling the RRA obj's underlying member method code with example usage: obj.last_best_fit() and returns: self