code: def columns(self, dimensions=None):
          
          if dimensions is None:
              dimensions = self.dimensions()
          else:
              dimensions = [self.get_dimension(d, strict=True) for d in dimensions]
          return OrderedDict([(d.name, self.dimension_values(d)) for d in dimensions])
docs: Convert dimension values to a dictionary.
  
          Returns a dictionary of column arrays along each dimension
          of the element.
  
          Args:
              dimensions: Dimensions to return as columns
  
          Returns:
              Dictionary of arrays for each dimension