class RSpec::Mocks::AnyInstance::Recorder

def unstub(method_name)
  unless @observed_methods.include?(method_name.to_sym)
    raise RSpec::Mocks::MockExpectationError, "The method `#{method_name}` was not stubbed or was already unstubbed"
  end
  message_chains.remove_stub_chains_for!(method_name)
  ::RSpec::Mocks.proxies_of(@klass).each do |proxy|
    stubs[method_name].each { |stub| proxy.remove_single_stub(method_name, stub) }
  end
  stubs[method_name].clear
  stop_observing!(method_name) unless message_chains.has_expectation?(method_name)
end