def _reaction_po_to_dict(tokens) -> Reaction:
    """Convert a reaction parse object to a DSL.

    :type tokens: ParseResult
    """
    return Reaction(
        reactants=_reaction_part_po_to_dict(tokens[REACTANTS]),
        products=_reaction_part_po_to_dict(tokens[PRODUCTS]),
    )
Convert a reaction parse object to a DSL.

    :type tokens: ParseResult