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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 _prepare_resource_chunks(self, resources, resource_delim=','):
 """As in some VirusTotal API methods the call can be made for multiple resources at once this method prepares a list of concatenated resources according to the maximum number of resources per requests. Args: resources: a list of the resources. resource_delim: a string used to separate the resources. Default value is a comma. Returns: A list of the concatenated resources. """

        return [self._prepare_resource_chunk(resources, resource_delim, pos)
                for pos in range(0, len(resources), self._resources_per_req)]