code: def pearson_fcn(self, B, x):
      return B[0] + B[1] * x
  
imports: from __future__ import division, print_function, absolute_import
  import numpy
  from numpy import pi
  from numpy.testing import assert_array_almost_equal, assert_equal, assert_warns
  from pytest import raises
  from scipy.odr import Data, Model, ODR, RealData, OdrStop, OdrWarning
label_desc: Use image node_id 12 for calling the TestODR obj's underlying member method code with example usage: obj.pearson_fcn(B, x) and returns: unknown