def get_column(name_or_column)
      # it's a column
      return name_or_column if name_or_column.is_a? ActiveScaffold::DataStructures::Column
      # it's a name
      name_or_column = name_or_column.to_s.split('.').last if name_or_column.to_s.include? '.'
      @columns[name_or_column]
    end
def get_column(name_or_column)
      # it's a column
      return name_or_column if name_or_column.is_a? ActiveScaffold::DataStructures::Column
      # it's a name
      name_or_column = name_or_column.to_s.split('.').last if name_or_column.to_s.include? '.'
      @columns[name_or_column]
    end
possibly converts the given argument into a column object from @columns (if it's not already)