class_docstr: A class which manages a mapping from functions to arguments and an inverse
  mapping from arguments to functions.
docstr: Return a set of functions each of which whose argument list contains
  ``argset``, optionally filtered only to contain functions in
  ``restrict_to_funcset``.
docstr_tok: ["Return","a","set","of","functions","each","of","which","whose","argument","list","contains","``","argset","``",",","optionally","filtered","only","to","contain","functions","in","``","restrict_to_funcset","``","."]
code: def get_subset_candidates(self, argset, restrict_to_funcset=None):
      """
      Return a set of functions each of which whose argument list contains
      ``argset``, optionally filtered only to contain functions in
      ``restrict_to_funcset``.
      """
      iarg = iter(argset)
  
      indices = OrderedSet(fi for fi in self.arg_to_funcset[next(iarg)])
  
      if restrict_to_funcset is not None:
          indices &= restrict_to_funcset
  
      for arg in iarg:
          indices &= self.arg_to_funcset[arg]
  
      return indices
  
imports: from collections import defaultdict
  from sympy.core import Basic, Mul, Add, Pow, sympify
  from sympy.core.containers import Tuple, OrderedSet
  from sympy.core.exprtools import factor_terms
  from sympy.core.singleton import S
  from sympy.core.sorting import ordered
  from sympy.core.symbol import symbols, Symbol
  from sympy.matrices import MatrixBase, Matrix, ImmutableMatrix, SparseMatrix, ImmutableSparseMatrix
  from sympy.matrices.expressions import MatrixExpr, MatrixSymbol, MatMul, MatAdd, MatPow, Inverse
  from sympy.matrices.expressions.matexpr import MatrixElement
  from sympy.polys.rootoftools import RootOf
  from sympy.utilities.iterables import numbered_symbols, sift, topological_sort, iterable
  from .None import cse_opts
label_desc: Use image node_id 6 for calling the FuncArgTracker obj's underlying member method code with example usage: obj.get_subset_candidates(argset, restrict_to_funcset) and returns: indices