code: function isAncestor(instA, instB) {
  	  !('_hostNode' in instA) ? process.env.NODE_ENV !== 'production' ? invariant(false, 'isAncestor: Invalid argument.') : _prodInvariant('35') : void 0;
  	  !('_hostNode' in instB) ? process.env.NODE_ENV !== 'production' ? invariant(false, 'isAncestor: Invalid argument.') : _prodInvariant('35') : void 0;
  
  	  while (instB) {
  	    if (instB === instA) {
  	      return true;
  	    }
  	    instB = instB._hostParent;
  	  }
  	  return false;
  	}
docs: Return if A is an ancestor of B.