code: def effect_expression(self, expression_levels):
          
          return OrderedDict(
              (effect, expression_levels.get(effect.transcript.id, 0.0))
              for effect in self
              if effect.transcript is not None)
docs: Parameters
          ----------
          expression_levels : dict
              Dictionary mapping transcript IDs to length-normalized expression
              levels (either FPKM or TPM)
  
          Returns dictionary mapping each transcript effect to an expression
          quantity. Effects that don't have an associated transcript
          (e.g. Intergenic) will not be included.