Fix superfluid oracle

- `is_available` implementation was not ok
- Related to #381

gnosis/eth/oracles/superfluid.py

@@ -26,11 +26,11 @@ def is_available(
         :param ethereum_client:
         :return: `True` if Oracle is available for the EthereumClient provided, `False` otherwise
         """
-        return (
-            ethereum_client.get_network() == EthereumNetwork.MATIC
-            or EthereumNetwork.XDAI
-            or EthereumNetwork.ARBITRUM
-            or EthereumNetwork.OPTIMISTIC
+        return ethereum_client.get_network() in (
+            EthereumNetwork.MATIC,
+            EthereumNetwork.XDAI,
+            EthereumNetwork.ARBITRUM,
+            EthereumNetwork.OPTIMISTIC,
         )
 
     def get_price(self, token_address: str) -> float:

gnosis/eth/tests/oracles/test_superfluid.py

@@ -5,14 +5,16 @@
 from ... import EthereumClient
 from ...oracles import CannotGetPriceFromOracle, SuperfluidOracle, SushiswapOracle
 from ..ethereum_test_case import EthereumTestCaseMixin
+from ..test_oracles import gno_token_mainnet_address
 from ..utils import just_test_if_polygon_node
 
-gno_token_mainnet_address = "0x6810e776880C02933D47DB1b9fc05908e5386b96"
-
 
 class TestSuperfluidOracle(EthereumTestCaseMixin, TestCase):
     def test_get_price(self):
         polygon_node = just_test_if_polygon_node()
+
+        self.assertFalse(SuperfluidOracle.is_available(self.ethereum_client))
+
         ethereum_client_polygon = EthereumClient(polygon_node)
 
         self.assertTrue(SuperfluidOracle.is_available(ethereum_client_polygon))