          # File lib/eventmachine.rb, line 1229
    1229:         def EventMachine::error_handler cb = nil, &blk
    1230:                 if cb or blk
    1231:                         @error_handler = cb || blk
    1232:                 elsif instance_variable_defined? :@error_handler
    1233:                         remove_instance_variable :@error_handler
    1234:                 end
    1235:         end