def ancestry_path(to_s_column = _ct.name_column)
      self_and_ancestors.map { |n| n.send to_s_column.to_sym }.reverse
    end
def ancestry_path(to_s_column = _ct.name_column)
      self_and_ancestors.map { |n| n.send to_s_column.to_sym }.reverse
    end
Returns an array, root first, of self_and_ancestors' values of the +to_s_column+, which defaults
 to the +name_column+.
 (so child.ancestry_path == +%w{grandparent parent child}+