Configures YAML parser for Step serialization and deserialization
    Called in drain/__init__.py

def configure():
    """
    Configures YAML parser for Step serialization and deserialization
    Called in drain/__init__.py
    """
    yaml.add_multi_representer(Step, step_multi_representer)
    yaml.add_multi_constructor('!step', step_multi_constructor)
    yaml.Dumper.ignore_aliases = lambda *args: True