add dummy calibration

src/depiction/calibration/spectrum/calibration_method_dummy.py

@@ -0,0 +1,24 @@
+from depiction.calibration.calibration_method import CalibrationMethod
+from numpy.typing import NDArray
+from xarray import DataArray
+
+
+class CalibrationMethodDummy(CalibrationMethod):
+    """Returns the input data and creates some dummy coefficients to ensure compatibility."""
+
+    def extract_spectrum_features(self, peak_mz_arr: NDArray[float], peak_int_arr: NDArray[float]) -> DataArray:
+        return DataArray([0], dims=["c"])
+
+    def preprocess_image_features(self, all_features: DataArray) -> DataArray:
+        return all_features
+
+    def fit_spectrum_model(self, features: DataArray) -> DataArray:
+        return features
+
+    def apply_spectrum_model(
+        self, spectrum_mz_arr: NDArray[float], spectrum_int_arr: NDArray[float], model_coef: DataArray
+    ) -> tuple[NDArray[float], NDArray[float]]:
+        return spectrum_mz_arr, spectrum_int_arr
+
+    def __repr__(self) -> str:
+        return f"{self.__class__.__name__}()"