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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 _init_get_dict():
 """Initialize dictionary for filter operations."""

        get_dict = {'main chain': PandasPdb._get_mainchain,
                    'hydrogen': PandasPdb._get_hydrogen,
                    'c-alpha': PandasPdb._get_calpha,
                    'carbon': PandasPdb._get_carbon,
                    'heavy': PandasPdb._get_heavy}
        return get_dict