code: def nul(self):
          r'''Kinematic viscosity of the liquid phase of the chemical at its
          current temperature and pressure, in units of [m^2/s].
  
          .. math::
              \nu = \frac{\mu}{\rho}
  
          Utilizes the temperature and pressure dependent object oriented
          interfaces :obj:`thermo.volume.VolumeLiquid`,
          :obj:`thermo.viscosity.ViscosityLiquid`  to calculate the
          actual properties.
  
          Examples
          --------
          >>> Chemical('methane', T=110).nul
          2.858088468937331e-07
          '''
          mul, rhol = self.mul, self.rhol
          if all([mul, rhol]):
              return nu_mu_converter(mu=mul, rho=rhol)
          return Nonf nul(self):
          r'''Kinematic viscosity of the liquid phase of the chemical at its
          current temperature and pressure, in units of [m^2/s].
  
          .. math::
              \nu = \frac{\mu}{\rho}
  
          Utilizes the temperature and pressure dependent object oriented
          interfaces :obj:`thermo.volume.VolumeLiquid`,
          :obj:`thermo.viscosity.ViscosityLiquid`  to calculate the
          actual properties.
  
          Examples
          --------
          >>> Chemical('methane', T=110).nul
          2.858088468937331e-07
          '''
          mul, rhol = self.mul, self.rhol
          if all([mul, rhol]):
              return nu_mu_converter(mu=mul, rho=rhol)
          return None
docs: r'''Kinematic viscosity of the liquid phase of the chemical at its
          current temperature and pressure, in units of [m^2/s].
  
          .. math::
              \nu = \frac{\mu}{\rho}
  
          Utilizes the temperature and pressure dependent object oriented
          interfaces :obj:`thermo.volume.VolumeLiquid`,
          :obj:`thermo.viscosity.ViscosityLiquid`  to calculate the
          actual properties.
  
          Examples
          --------
          >>> Chemical('methane', T=110).nul
          2.858088468937331e-07