class_docstr: An Agent class for all optimization techniques.
class_docstr_tok: ["An","Agent","class","for","all","optimization","techniques","."]
code: def n_variables(self, n_variables: int) -> None:
      if not isinstance(n_variables, int):
          raise e.TypeError("`n_variables` should be an integer")
      if n_variables <= 0:
          raise e.ValueError("`n_variables` should be > 0")
  
      self._n_variables = n_variables
  
imports: import time
  from typing import Dict, List, Optional, Union
  import numpy
  import opytimizer.math.random
  import opytimizer.utils.constant
  import opytimizer.utils.exception
  from opytimizer.utils import logging
label_desc: Use image node_id 3 for calling the Agent obj's underlying member method code with example usage: obj.n_variables(n_variables) without return types