def _trace_S(s, j, b, S_cosets):
    for h in S_cosets[b]:
        if s[h[b]] == j:
            return h
    return None
A private observer which invalidates the layout.
dataset/ETHPy150Open sympy/sympy/sympy/combinatorics/tensor_can.py/_trace_S--crossover with--dataset/ETHPy150Open ContinuumIO/ashiba/enaml/enaml/widgets/container.py/Container._layout_invalidated