code: def set_implementation(self, impl):
          
          if impl.lower() == 'python':
              self.__impl__ = self.__IMPL_PYTHON__
          elif impl.lower() == 'c':
              self.__impl__ = self.__IMPL_C__
          else:
              import warnings
              warnings.warn('Implementation '+impl+' is not known. Using the fallback python implementation.')
              self.__impl__ = self.__IMPL_PYTHON__
docs: Sets the implementation of this module
  
          Parameters
          ----------
          impl : str
              One of ["python", "c"]