def deterministic(__func__=None, **kwds):
    """
    Decorator function instantiating deterministic variables. Usage:

    @deterministic
    def B(parent_name = ., ...)
        return baz(parent_name, ...)

    @deterministic(trace = trace_object)
    def B(parent_name = ., ...)
        return baz(parent_name, ...)

    where baz returns the variable B's value conditional
    on its parents.

    :SeeAlso:
      Deterministic, Potential, potential, Stochastic, stochastic, data, Model,
      CommonDeterministics
    """
    def instantiate_n(__func__):
        junk, parents = _extract(
            __func__, kwds, keys, 'Deterministic', probe=False)
        return Deterministic(parents=parents, **kwds)

    keys = ['eval']

    instantiate_n.kwds = kwds

    if __func__:
        return instantiate_n(__func__)

    return instantiate_n