# File kwartz.rb, line 2691
        def analyze
            return nil if @node == nil
            @node.execute(self)
            @globals = []
            @locals  = []
            @variables.each do |varname, data|
                case data[:scope]
                when :global
                    @globals << varname
                when :local
                    @locals  << varname
                end
            end
        end