python.processes.external.external_base.ExternalBase Node1 python.processes.external.external _base.ExternalBase + name + executable + __init__() + needs_scheduling() Node2 python.processes.configurable. Configurable + parameters + __init__() + add_keyword() + expose() + has_keyword() + has_parameter() + parameters_by_keyword() + parameters_by_name() Node2->Node1 Node3 object Node3->Node2