'Initialize enabled agent extensions.
:param connection: RPC connection that can be reused by extensions to
define their RPC endpoints
:param driver_type: a string that defines the agent type to the
extension. Can be used by the extension to choose
the right backend implementation.
:param agent_api: an AgentAPI instance that provides an API to
interact with the agent that the manager
is running in.'

def initialize(self, connection, driver_type, agent_api=None):

    for extension in self:
        LOG.info(_LI("Initializing    agent    extension    '%s'"), extension.name)
        extension.obj.consume_api(agent_api)
        extension.obj.initialize(connection, driver_type)
