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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 _update_from_body(self, destination, source):
 """Updates the dictionary for an API payload with the request body. The values from the body should override those already in the payload, but for nested fields (message objects) the values can be combined recursively. Args: destination: A dictionary containing an API payload parsed from the path and query parameters in a request. source: A dictionary parsed from the body of the request. """

    for key, value in source.iteritems():
      destination_value = destination.get(key)
      if isinstance(value, dict) and isinstance(destination_value, dict):
        self._update_from_body(destination_value, value)
      else:
        destination[key] = value