def _usage():
    """
    Return usage of the main ivy call and an example.
    """
    usage = """
    **Ivy workflow engine**
    Copyright (c) 2014 ETH Zurich, Institute for Astronomy

    Usage:
    ivy [arguments] configuration

    Only arguments already preconfigured in the given configuration will be accepted.
    Note: Dashed '-' will be converted into underlines '_' for all the arguments

    example:
    - ivy --size-x=100 --size-y=100 ufig.config.random
    """
    print(usage)
