code: def call(self, _from=None, to=None, gas=None, gas_price=None, value=0,
               data=None, block="latest"):
          
          if _from is None:
              _from = self.default_from_address
  
          params = [
              get_transaction_params(_from, to, gas, gas_price, value, data),
              block,
          ]
          response = self.make_request("eth_call", params)
          return response['result']
docs: https://github.com/ethereum/wiki/wiki/JSON-RPC#eth_call