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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 get_parameter_definitions(self):
 """Get the parameter definitions to submit to CloudFormation. Any variable definition whose `type` is an instance of `CFNType` will be returned as a CloudFormation Parameter. Returns: dict: parameter definitions. Keys are parameter names, the values are dicts containing key/values for various parameter properties. """

        output = {}
        for var_name, attrs in self.defined_variables().items():
            var_type = attrs.get("type")
            if isinstance(var_type, CFNType):
                cfn_attrs = copy.deepcopy(attrs)
                cfn_attrs["type"] = var_type.parameter_type
                output[var_name] = cfn_attrs
        return output