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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 _check_dep(self, depinfo, deptile, resolver):
 """Check if a dependency tile is up to date Returns: bool: True if it is up to date, False if it not and None if this resolver cannot assess whether or not it is up to date. """


        try:
            settings = self._load_depsettings(deptile)
        except IOError:
            return False

        # If this dependency was initially resolved with a different resolver, then
        # we cannot check if it is up to date
        if settings['resolver'] != resolver.__class__.__name__:
            return None

        resolver_settings = {}
        if 'settings' in settings:
            resolver_settings = settings['settings']

        return resolver.check(depinfo, deptile, resolver_settings)