code: def _run(
      self,
      mat: np.ndarray,
      split: Optional[np.ndarray] = None,
      axis: int = 0,
      keepdims: int = 1,
  ) -> Tuple[np.ndarray]:
      res = self.common_run(mat, split, axis=axis)
      if split is None and not keepdims:
          for i in range(len(res)):
              shape = list(res[i].shape)
              del shape[axis]
              res[i] = res[i].reshape(tuple(shape))
      return (res,)
  
imports: from typing import List, Optional, Tuple
  import numpy
  from onnx.reference.op_run import OpRun
label_desc: Use image node_id 2 for calling the SplitToSequence obj's underlying member method code with example usage: obj._run(mat, split, axis, keepdims) and returns: res