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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 handle_namespace_pattern(self, line: str, position: int, tokens: ParseResults) -> ParseResults: """Handle statements like ``DEFINE NAMESPACE X AS PATTERN "Y"``. :raises: RedefinedNamespaceError """

        namespace = tokens['name']
        self.raise_for_redefined_namespace(line, position, namespace)
        self.namespace_to_pattern[namespace] = re.compile(tokens['value'])
        return tokens