From 58714888587a3c9ec44cf55da8f07f62973e4609 Mon Sep 17 00:00:00 2001
From: Gert Wohlgemuth <wohlgemuth@ucdavis.edu>
Date: Mon, 16 Jul 2018 20:40:17 -0700
Subject: [PATCH] fixed errors and making flake pass

---
 freqtrade/strategy/interface.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/freqtrade/strategy/interface.py b/freqtrade/strategy/interface.py
index 94098a63a..213546497 100644
--- a/freqtrade/strategy/interface.py
+++ b/freqtrade/strategy/interface.py
@@ -70,6 +70,7 @@ class IStrategy(ABC):
     def __init__(self, config: dict) -> None:
         self.config = config
 
+    @abstractmethod
     def populate_indicators(self, dataframe: DataFrame) -> DataFrame:
         """
         Populate indicators that will be used in the Buy and Sell strategy
@@ -80,6 +81,7 @@ class IStrategy(ABC):
                       DeprecationWarning)
         return dataframe
 
+    @abstractmethod
     def populate_buy_trend(self, dataframe: DataFrame) -> DataFrame:
         """
         Based on TA indicators, populates the buy signal for the given dataframe
@@ -91,6 +93,7 @@ class IStrategy(ABC):
         dataframe.loc[(), 'buy'] = 0
         return dataframe
 
+    @abstractmethod
     def populate_sell_trend(self, dataframe: DataFrame) -> DataFrame:
         """
         Based on TA indicators, populates the sell signal for the given dataframe