@staticmethod
def to_nullable_array(value):
    """
        Converts value into array object.
        Single values are converted into arrays with a single element.

        :param value: the value to convert.

        :return: array object or None when value is None.
        """
    if value == None:
        return None
    if type(value) == list:
        return value
    if type(value) in [tuple, set]:
        return list(value)
    return [value]
