code: def einsum_reference_implementation(
      Eqn: str, Operands: Tuple[np.ndarray, ...]
  ) -> np.ndarray:
      Z = np.einsum(Eqn, *Operands)
      return Z
  
file_path: onnx/onnx/backend/test/case/node/einsum.py
imports: from typing import Tuple
  import numpy
  import onnx
  from onnx.backend.test.case.base import Base
  from onnx.backend.test.case.node import expect
label_desc: Use image node_id 1 for calling a global function with example usage: einsum_reference_implementation(Eqn, Operands) and returns: Z