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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 _create_product_map(self):
 """Create a map of all products produced by this or a dependency."""


        self._product_map = {}

        for dep in self._tile.dependencies:
            try:
                dep_tile = IOTile(os.path.join('build', 'deps', dep['unique_id']))
            except (ArgumentError, EnvironmentError):
                raise BuildError("Could not find required dependency", name=dep['name'])

            self._add_products(dep_tile)

        self._add_products(self._tile, show_all=True)