class_docstr: Helper class to return a subsequence of values.
code: def __call__(self, m):
      return tuple(m[idx] for idx in self.seq)
  
imports: from __future__ import annotations
  from sympy.core import Symbol
  from sympy.utilities.iterables import iterable
label_desc: Use image node_id 2 for calling the _ItemGetter obj's underlying member method code with example usage: obj.__call__(m) and returns: tuple