class_docstr: Cigar objective function.
  
  This class defines the Cigar [1]_ global optimization problem. This
  is a multimodal minimization problem defined as follows:
  
  .. math::
  
      f_{\text{Cigar}}(x) = x_1^2 + 10^6\sum_{i=2}^{n} x_i^2
  
  
  Here, :math:`n` represents the number of dimensions and :math:`x_i \in
  [-100, 100]` for :math:`i = 1, ..., n`.
  
  *Global optimum*: :math:`f(x) = 0` for :math:`x_i = 0` for
  :math:`i = 1, ..., n`
  
  .. [1] Gavana, A. Global Optimization Benchmarks and AMPGO retrieved 2015
code: def fun(self, x, *args):
      self.nfev += 1
  
      return x[0] ** 2 + 1e6 * sum(x[1:] ** 2)
  
imports: import numpy
  from numpy import abs, asarray, cos, exp, floor, pi, sign, sin, sqrt, sum, size, tril, isnan, atleast_2d, repeat
  from numpy.testing import assert_almost_equal
  from .go_benchmark import Benchmark
label_desc: Use image node_id 2 for calling the Cigar obj's underlying member method code with example usage: obj.fun(x) and returns: unknown