code: def get_validators(cls, bigchain, height=None):
          
          validators = {}
          for validator in bigchain.get_validators(height):
              # NOTE: we assume that Tendermint encodes public key in base64
              public_key = public_key_from_ed25519_key(key_from_base64(validator['public_key']['value']))
              validators[public_key] = validator['voting_power']
  
          return validators
docs: Return a dictionary of validators with key as `public_key` and
             value as the `voting_power`