# File lib/erubis/context.rb, line 65
    def update(context_or_hash)
      arg = context_or_hash
      if arg.is_a?(Hash)
        arg.each do |key, val|
          self[key] = val
        end
      else
        arg.instance_variables.each do |varname|
          key = varname[1..-1]
          val = arg.instance_variable_get(varname)
          self[key] = val
        end
      end
    end