code: def as_immutable(self):
      return ImmutableSparseNDimArray(self)
  
imports: from sympy.core.basic import Basic
  from sympy.core.containers import Dict, Tuple
  from sympy.core.singleton import S
  from sympy.core.sympify import _sympify
  from sympy.tensor.array.mutable_ndim_array import MutableNDimArray
  from sympy.tensor.array.ndim_array import NDimArray, ImmutableNDimArray
  from sympy.utilities.iterables import flatten
  import functools
label_desc: Use image node_id 3 for calling the MutableSparseNDimArray obj's underlying member method code with example usage: obj.as_immutable() and returns: ImmutableSparseNDimArray