def _locate_element(dom, el_content, transformer=None):
    """
    Find element containing `el_content` in `dom`. Use `transformer` function
    to content of all elements in `dom` in order to correctly transforming them
    to match them with `el_content`.

    Args:
        dom (obj): HTMLElement tree.
        el_content (str): Content of element will be picked from `dom`.
        transformer (fn, default None): Transforming function.

    Note:
        `transformer` parameter can be for example simple lambda::

            lambda x: x.strip()

    Returns:
        list: Matching HTMLElements.
    """
    return dom.find(
        None,
        fn=utils.content_matchs(el_content, transformer)
    )
Find element containing `el_content` in `dom`. Use `transformer` function
    to content of all elements in `dom` in order to correctly transforming them
    to match them with `el_content`.

    Args:
        dom (obj): HTMLElement tree.
        el_content (str): Content of element will be picked from `dom`.
        transformer (fn, default None): Transforming function.

    Note:
        `transformer` parameter can be for example simple lambda::

            lambda x: x.strip()

    Returns:
        list: Matching HTMLElements.