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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 generate_handler_sourcepath( self, toolchain, spec, loaderplugin_sourcepath):
 """ The default implementation is a recursive lookup method, which subclasses may make use of. Subclasses must implement this to return a mapping of modnames the the absolute path of the desired sourcefiles. Example: return { 'text': '/tmp/src/example_module/text/index.js', 'json': '/tmp/src/example_module/json/index.js', } Subclasses of this implementation must accept the same arguments, and they should invoke this implementation via super and merge its results (e.g. using dict.update) with one provided by this one. Also, this implementation depends on a correct unwrap implementation for the loaderplugin at hand, if required. """


        # since the loaderplugin_sourcepath values is the complete
        # modpath with the loader plugin, the values must be stripped
        # before making use of the filtering helper function for
        # grouping the inner mappings
        fake_spec = {}
        registry = spec.get(CALMJS_LOADERPLUGIN_REGISTRY)
        if registry:
            fake_spec[CALMJS_LOADERPLUGIN_REGISTRY] = registry
        spec_update_sourcepath_filter_loaderplugins(fake_spec, {
            self.unwrap(k): v
            for k, v in loaderplugin_sourcepath.items()
        }, 'current', 'nested')
        result = {}
        for plugin_name, sourcepath in fake_spec['nested'].items():
            if sourcepath == loaderplugin_sourcepath:
                logger.warning(
                    "loaderplugin '%s' extracted same sourcepath of while "
                    "locating chain loaders: %s; skipping",
                    self.name, sourcepath
                )
                continue
            plugin = self.registry.get_record(plugin_name)
            if not plugin:
                logger.warning(
                    "loaderplugin '%s' from registry '%s' cannot find "
                    "sibling loaderplugin handler for '%s'; processing "
                    "may fail for the following nested/chained sources: "
                    "%s",
                    self.name, self.registry.registry_name, plugin_name,
                    sourcepath,
                )
                continue
            result.update(plugin.generate_handler_sourcepath(
                toolchain, spec, sourcepath))
        return result