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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def ifilter(self, recursive=True, matches=None, flags=FLAGS, forcetype=None):
 """Iterate over nodes in our list matching certain conditions. If *forcetype* is given, only nodes that are instances of this type (or tuple of types) are yielded. Setting *recursive* to ``True`` will iterate over all children and their descendants. ``RECURSE_OTHERS`` will only iterate over children that are not the instances of *forcetype*. ``False`` will only iterate over immediate children. ``RECURSE_OTHERS`` can be used to iterate over all un-nested templates, even if they are inside of HTML tags, like so: ["{{foo}}", "{{foo|{{bar}}}}"] *matches* can be used to further restrict the nodes, either as a function (taking a single :class:`.Node` and returning a boolean) or a regular expression (matched against the node's string representation with :func:`re.search`). If *matches* is a regex, the flags passed to :func:`re.search` are :const:`re.IGNORECASE`, :const:`re.DOTALL`, and :const:`re.UNICODE`, but custom flags can be specified by passing *flags*. """

        gen = self._indexed_ifilter(recursive, matches, flags, forcetype)
        return (node for i, node in gen)