Serialize a sequence of Python objects into a YAML stream.
    Produce only basic YAML tags.
    If stream is None, return the produced string instead.

def safe_dump_all(documents, stream=None, **kwds):
    """
    Serialize a sequence of Python objects into a YAML stream.
    Produce only basic YAML tags.
    If stream is None, return the produced string instead.
    """
    return dump_all(documents, stream, Dumper=SafeDumper, **kwds)