code: def _get_lambda_evaluator(self):
      fx, fy, fz = self.d_vars
      u = self.u_interval.v
      v = self.v_interval.v
      return lambdify([u, v], [fx, fy, fz])
  
imports: from sympy.utilities.lambdify import lambdify
  from sympy.core.numbers import pi
  from sympy.functions import sin, cos
  from sympy.plotting.pygletplot.plot_curve import PlotCurve
  from sympy.plotting.pygletplot.plot_surface import PlotSurface
  from math import sin
  from math import cos
label_desc: Use image node_id 2 for calling the ParametricSurface obj's underlying member method code with example usage: obj._get_lambda_evaluator() and returns: lambdify