code: def _get_key_props(phase=None, diameter='throat.diameter',
                     surface_tension='pore.surface_tension',
                     contact_angle='pore.contact_angle'):
      r
      element = diameter.split('.')[0]
      if element == 'pore':
          if 'throat' in surface_tension:
              sigma = phase.interpolate_data(propname=surface_tension)
          else:
              sigma = phase[surface_tension]
          if 'throat' in contact_angle:
              theta = phase.interpolate_data(propname=contact_angle)
          else:
              theta = phase[contact_angle]
      if element == 'throat':
          if 'pore' in surface_tension:
              sigma = phase.interpolate_data(propname=surface_tension)
          else:
              sigma = phase[surface_tension]
          if 'pore' in contact_angle:
              theta = phase.interpolate_data(propname=contact_angle)
          else:
              theta = phase[contact_angle]
  
      return element, sigma, theta
docs: r"""
      Many of the methods are generic to pores and throats. Some information may
      be stored on either the pore or throat and needs to be interpolated.
      This is a helper method to return the properties in the correct format.
      To do:
          Check for method to convert throat to pore data