<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def serialize_properties(properties):
 """Serialize properties. Parameters properties : dict Properties to serialize. """

    new_properties = properties.copy()
    for attr_name, attr_value in new_properties.items():
        if isinstance(attr_value, datetime):
            new_properties[attr_name] = attr_value.isoformat()
        elif not isinstance(attr_value, (dict, list, tuple, str, int, float, bool, type(None))):
            # Property is not JSON-serializable according to this table
            # https://docs.python.org/3.4/library/json.html#json.JSONEncoder
            # so we convert to string
            new_properties[attr_name] = str(attr_value)
    return new_properties