class_docstr: A GSA class, inherited from Optimizer.
  
  This is the designed class to define GSA-related
  variables and methods.
  
  References:
      E. Rashedi, H. Nezamabadi-Pour and S. Saryazdi. GSA: a gravitational search algorithm.
      Information Sciences (2009).
class_docstr_tok: ["A","GSA","class",",","inherited","from","Optimizer",".","This","is","the","designed","class","to","define","GSA-related","variables","and","methods",".","References",":","E.","Rashedi",",","H.","Nezamabadi-Pour","and","S.","Saryazdi",".","GSA",":","a","gravitational","search","algorithm",".","Information","Sciences","(","2009",")","."]
docstr: Array of velocities.
docstr_tok: ["Array","of","velocities","."]
code: def velocity(self) -> np.ndarray:
      """Array of velocities."""
  
      return self._velocity
  
imports: from typing import Any, Dict, List, Optional
  import numpy
  import opytimizer.math.general
  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.space import Space
  from opytimizer.utils import logging
label_desc: Use image node_id 4 for calling the GSA obj's underlying member method code with example usage: obj.velocity() and returns: self