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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 _gen_modname_source_target_modpath(self, spec, d):
 """ Private generator that will consume those above functions. This should NOT be overridden. Produces the following 4-tuple on iteration with the input dict; the definition is written at the module level documention for calmjs.toolchain, but in brief: modname The JavaScript module name. source Stands for sourcepath - path to some JavaScript source file. target Stands for targetpath - the target path relative to spec[BUILD_DIR] where the source file will be written to using the method that genearted this entry. modpath The module path that is compatible with tool referencing the target. While this is typically identical with modname, some tools require certain modifications or markers in additional to what is presented (e.g. such as the addition of a '?' symbol to ensure absolute lookup). """


        for modname_source in d.items():
            try:
                modname = self.modname_source_to_modname(spec, *modname_source)
                source = self.modname_source_to_source(spec, *modname_source)
                target = self.modname_source_to_target(spec, *modname_source)
                modpath = self.modname_source_target_modnamesource_to_modpath(
                    spec, modname, source, target, modname_source)
            except ValueError as e:
                # figure out which of the above 3 functions failed by
                # acquiring the name from one frame down.
                f_name = sys.exc_info()[2].tb_next.tb_frame.f_code.co_name

                if isinstance(e, ValueSkip):
                    # a purposely benign failure.
                    log = partial(
                        logger.info,
                        "toolchain purposely skipping on '%s', "
                        "reason: %s, where modname='%s', source='%s'",
                    )
                else:
                    log = partial(
                        logger.warning,
                        "toolchain failed to acquire name with '%s', "
                        "reason: %s, where modname='%s', source='%s'; "
                        "skipping",
                    )

                log(f_name, e, *modname_source)
                continue
            yield modname, source, target, modpath