class_docstr: A BOA class, inherited from Optimizer.
  
  This is the designed class to define BOA-related
  variables and methods.
  
  References:
      S. Arora and S. Singh. Butterfly optimization algorithm: a novel approach for global optimization.
      Soft Computing (2019).
code: def a(self, a: float) -> None:
      if not isinstance(a, (float, int)):
          raise e.TypeError("`a` should be a float or integer")
      if a < 0:
          raise e.ValueError("`a` should be >= 0")
  
      self._a = a
  
imports: from typing import Any, Dict, Optional
  import numpy
  import opytimizer.math.random
  import opytimizer.utils.exception
  from opytimizer.core import Optimizer
  from opytimizer.core.space import Space
  from opytimizer.utils import logging
label_desc: Use image node_id 5 for calling the BOA obj's underlying member method code with example usage: obj.a(a) without return types