class_docstr: This is a benchmark of unidimensional functions interesting to optimize. 
  :param bounds: the box constraints to define the domain in which the function is optimized.
code: def plot(self, bounds=None):
      if bounds is None:
          bounds = self.bounds
      X = np.arange(bounds[0][0], bounds[0][1], 0.01)
      Y = self.f(X)
      plt.plot(X, Y, lw=2)
      plt.xlabel("x")
      plt.ylabel("f(x)")
      plt.show()
  
imports: import matplotlib.pyplot
  import numpy
label_desc: Use image node_id 1 for calling the function1d obj's underlying member method code with example usage: obj.plot(bounds) without return types