def wfind(self, tag_name, params=None, fn=None, case_sensitive=False):
        """
        This methods works same as :meth:`find`, but only in one level of the
        :attr:`childs`.

        This allows to chain :meth:`wfind` calls::

            >>> dom = dhtmlparser.parseString('''
            ... <root>
            ...     <some>
            ...         <something>
            ...             <xe id="wanted xe" />
            ...         </something>
            ...         <something>
            ...             asd
            ...         </something>
            ...         <xe id="another xe" />
            ...     </some>
            ...     <some>
            ...         else
            ...         <xe id="yet another xe" />
            ...     </some>
            ... </root>
            ... ''')
            >>> xe = dom.wfind("root").wfind("some").wfind("something").find("xe")
            >>> xe
            [<dhtmlparser.htmlelement.HTMLElement object at 0x8a979ac>]
            >>> str(xe[0])
            '<xe id="wanted xe" />'

        Args:
            tag_name (str): Name of the tag you are looking for. Set to "" if
                            you wish to use only `fn` parameter.
            params (dict, default None): Parameters which have to be present
                   in tag to be considered matching.
            fn (function, default None): Use this function to match tags.
               Function expects one parameter which is HTMLElement instance.
            case_sensitive (bool, default False): Use case sensitive search.

        Returns:
            obj: Blank HTMLElement with all matches in :attr:`childs` property.

        Note:
            Returned element also have set :attr:`_container` property to True.
        """
        childs = self.childs
        if self._container:  # container object
            childs = map(
                lambda x: x.childs,
                filter(lambda x: x.childs, self.childs)
            )
            childs = sum(childs, [])  # flattern the list

        el = self.__class__()  # HTMLElement()
        el._container = True
        for child in childs:
            if child.isEndTag():
                continue

            if child.isAlmostEqual(tag_name, params, fn, case_sensitive):
                el.childs.append(child)

        return el