code: def calculate(self, **state):
          
  
          T = state['T']
          y = state['y']
          x = amount_fractions(y)
          return super().calculate(T=T, x=x)
docs: Calculate dynamic viscosity at the specified temperature and
          composition:
  
          :param T: [K] temperature
          :param y: [mass fraction] composition dictionary , e.g. \
          {'SiO2': 0.25, 'CaO': 0.25, 'MgO': 0.25, 'FeO': 0.25}
  
          :returns: [Pa.s] dynamic viscosity
  
          The **state parameter contains the keyword argument(s) specified above\
          that are used to describe the state of the material.