code: def find(self, dtype):
          
          if not isinstance(dtype, str):
              dtype_type = dtype
              if not isinstance(dtype, type):
                  dtype_type = type(dtype)
              if issubclass(dtype_type, ExtensionDtype):
                  return dtype
  
              return None
  
          for dtype_type in self.dtypes:
              try:
                  return dtype_type.construct_from_string(dtype)
              except TypeError:
                  pass
  
          return None
docs: Parameters
          ----------
          dtype : PandasExtensionDtype or string
  
          Returns
          -------
          return the first matching dtype, otherwise return None