text: from pandas.core.dtypes.dtypes import register_extension_dtype
  from .base import MTZFloatArray, MTZFloat32Dtype
  
  @register_extension_dtype
  class AnomalousDifferenceDtype(MTZFloat32Dtype):
      """Dtype for anomalous difference data in reflection tables"""
      name = 'AnomalousDifference'
      mtztype = "D"
      
      @classmethod
      def construct_array_type(cls):
          return AnomalousDifferenceArray
  
  class AnomalousDifferenceArray(MTZFloatArray):
      """ExtensionArray for supporting AnomalousDifferenceDtype"""
      _dtype = AnomalousDifferenceDtype()
      pass
  