code: def _scalar_func_2(self, s):
      self.fcount += 1
      p = np.exp(-4 * s) + s**2
      dp = -4 * np.exp(-4 * s) + 2 * s
      return p, dp
  
imports: from numpy.testing import assert_, assert_equal, assert_array_almost_equal, assert_array_almost_equal_nulp, assert_warns, suppress_warnings
  import scipy.optimize.linesearch
  from scipy.optimize.linesearch import LineSearchWarning
  import numpy
label_desc: Use image node_id 2 for calling the TestLineSearch obj's underlying member method code with example usage: obj._scalar_func_2(s) and returns: p,  dp