if (!isPlanarSigmaBond(cardinalBonds[NORTH]) || !isPlanarSigmaBond(cardinalBonds[SOUTH])) return null; if (isPlanarSigmaBond(cardinalBonds[EAST])) { neighbors[EAST] = cardinalBonds[EAST].getOther(focus); if (isPlanarSigmaBond(cardinalBonds[WEST])) { neighbors[WEST] = cardinalBonds[WEST].getOther(focus);