code: def approximation_parameters(
      method: str,
  ) -> Tuple[
      Callable[[int], List[float]], Callable[[int], List[float]]
  ]:
      """
      Retrieves parameters for the input approximation `method`.
  
      Parameters
      ----------
      method
          The name of the approximation method. Currently supported only: ``'riemann_*'`` and ``'gausslegendre``'.
          Check :py:data:`alibi.utils.approximation_methods.SUPPORTED_RIEMANN_METHODS` for all ``'riemann_*'`` possible
          values.
      """
      if method in SUPPORTED_RIEMANN_METHODS:
          return riemann_builders(method=Riemann[method.split("_")[-1]])
      if method == "gausslegendre":
          return gauss_legendre_builders()
      raise ValueError(
          "Invalid integral approximation method name: {}".format(
              method
          )
      )
  
imports: from typing import List, Callable, Tuple
  import numpy
  from enum import Enum
label_desc: Use image node_id 1 for calling a global function with example usage: approximation_parameters(method) and returns: riemann_builders, gauss_legendre_builders