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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 find_formatter_class(alias):
 """Lookup a formatter by alias. Returns None if not found. """

    for module_name, name, aliases, _, _ in itervalues(FORMATTERS):
        if alias in aliases:
            if name not in _formatter_cache:
                _load_formatters(module_name)
            return _formatter_cache[name]
    for _, cls in find_plugin_formatters():
        if alias in cls.aliases:
            return cls