feat:获取历史持仓

@@ -231,6 +231,13 @@ class BinanceFutures
         $method = 'GET';
         return self::requestMarket($method, $path, $param);
     }
+    //获取历史持仓
+    static public function openInterestHist($param)
+    {
+        $path   = '/futures/data/openInterestHist';
+        $method = 'GET';
+        return self::requestMarket($method, $path, $param);
+    }
 }
 
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