human
Complete this python program:
def _standardize_iterables(node):
assistant
#Here is the Python code you requested.

    """Converts the given iterables to a {field: function} dictionary,
    if necessary, where the function returns a list.
    """
    if (not node.iterables):
        return
    iterables = node.iterables
    fields = set(node.inputs.copyable_trait_names())
    synchronize = False
    if node.synchronize:
        if (len(iterables) == 2):
            (first, last) = iterables
            if all(((isinstance(item, (str, bytes)) and (item in fields)) for item in first)):
                iterables = _transpose_iterables(first, last)
    if isinstance(iterables, tuple):
        iterables = [iterables]
    _validate_iterables(node, iterables, fields)
    if isinstance(iterables, list):
        if (not node.itersource):
            def make_field_func(*pair):
                return (pair[0], (lambda : pair[1]))
            iter_items = [make_field_func(*field_value1) for field_value1 in iterables]
            iterables = dict(iter_items)
    node.iterables = iterables