from typing import List
from typing import Union


def ls_strip_elements(ls_elements: List[str], chars: Union[None, str] = None) -> List[str]:
    """
    >>> ls_strip_elements(['  a','bbb','   '])
    ['a', 'bbb', '']
    >>> ls_strip_elements([])
    []

    """

    if (not ls_elements) or (ls_elements is None):
        return list()
    return [s_element.strip(chars) for s_element in ls_elements]