Add Ptr KNearest::load and python binding

modules/ml/include/opencv2/ml.hpp

@@ -505,6 +505,14 @@ public:
     The static method creates empty %KNearest classifier. It should be then trained using StatModel::train method.
      */
     CV_WRAP static Ptr<KNearest> create();
+    /** @brief Loads and creates a serialized knearest from a file
+     *
+     * Use KNearest::save to serialize and store an KNearest to disk.
+     * Load the KNearest from this file again, by calling this function with the path to the file.
+     *
+     * @param filepath path to serialized KNearest
+     */
+    CV_WRAP static Ptr<KNearest> load(const String& filepath);
 };
 
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