code: def to_dataframe(self, columns=None):
      
      if not isinstance(self.measured_value, DimensionedMeasuredValue):
        raise TypeError(
          'Only a dimensioned measurement can be converted to a DataFrame')
  
      if columns is None:
        columns = [d.name for d in self.dimensions]
        columns += [self.units.name if self.units else 'value']
  
      dataframe = self.measured_value.to_dataframe(columns)
  
      return dataframe
docs: Convert a multi-dim to a pandas dataframe.