code: def lm_freqs_taus(**kwargs):
      
      lmns = kwargs['lmns']
      freqs, taus = {}, {}
  
      for lmn in lmns:
          l, m, nmodes = int(lmn[0]), int(lmn[1]), int(lmn[2])
          for n in range(nmodes):
              try:
                  freqs['%d%d%d' %(l,m,n)] = kwargs['f_%d%d%d' %(l,m,n)]
              except KeyError:
                  raise ValueError('f_%d%d%d is required' %(l,m,n))
              try:
                  taus['%d%d%d' %(l,m,n)] = kwargs['tau_%d%d%d' %(l,m,n)]
              except KeyError:
                  raise ValueError('tau_%d%d%d is required' %(l,m,n))
  
      return freqs, taus
docs: Take input_params and return dictionaries with frequencies and damping
      times of each overtone of a specific lm mode, checking that all of them
      are given.