Capistrano

# File lib/capistrano/extensions.rb, line 20
def self.plugin(name, mod)
  name = name.to_sym
  return false if EXTENSIONS.has_key?(name)

  methods = Capistrano::Configuration.public_instance_methods +
    Capistrano::Configuration.protected_instance_methods +
    Capistrano::Configuration.private_instance_methods

  if methods.any? { |m| m.to_sym == name }
    raise Capistrano::Error, "registering a plugin named `#{name}' would shadow a method on Capistrano::Configuration with the same name"
  end

  Capistrano::Configuration.class_eval       def #{name}        @__#{name}_proxy ||= Capistrano::ExtensionProxy.new(self, Capistrano::EXTENSIONS[#{name.inspect}])      end, __FILE__, __LINE__+1

  EXTENSIONS[name] = mod
  return true
end

# File lib/capistrano/extensions.rb, line 43
def self.remove_plugin(name)
  name = name.to_sym
  if EXTENSIONS.delete(name)
    Capistrano::Configuration.send(:remove_method, name)
    return true
  end

  return false
end

# File lib/capistrano/shell.rb, line 257
def sessions
  configuration.sessions.values
end