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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 regex(pattern, flags: int = 0):
 """Filter messages that match a given RegEx pattern. Args: pattern (``str``):
 The RegEx pattern as string, it will be applied to the text of a message. When a pattern matches, all the `Match Objects <https://docs.python.org/3/library/re.html#match-objects>`_ are stored in the *matches* field of the :class:`Message <pyrogram.Message>` itself. flags (``int``, *optional*):
 RegEx flags. """


        def f(_, m):
            m.matches = [i for i in _.p.finditer(m.text or m.caption or "")]
            return bool(m.matches)

        return create("Regex", f, p=re.compile(pattern, flags))