# File lib/declarative_authorization/development_support/development_support.rb, line 136
        def self.all_for_privilege (privilege, context, engine)
          privilege = privilege.is_a?(Symbol) ? Privilege.for_sym(privilege, engine) : privilege
          privilege_symbols = ([privilege] + privilege.ancestors).map(&:to_sym)
          all(engine).select {|role| role.rules.any? {|rule| rule.matches?([role.to_sym], privilege_symbols, context)}}.
              collect {|role| [role] + role.descendants}.flatten.uniq
        end