• #689: Support onnx==1.9.0
• #694: Support missing string values with SimpleImputer
• #692: Fix Scaler converter, fix OnnxSubEstimator not directly connected to the converter inputs
• #691: Remove trivial Runtime error in SVM converter
• #682: fix type issue in AdaBoostClassifier (apply_clip)
• #680: Support conversion of StandardScaler with Double and norm L2
• #677: Add annotation to converters and shape calculator
• #676: Remove dependency on six