code: function removeExponentByOne(node) {
    if (node.op === '^' &&                   // exponent of anything
        Node.Type.isConstant(node.args[1]) && // to a constant
        node.args[1].value === '1') {        // of value 1
      const newNode = clone(node.args[0]);
      return Node.Status.nodeChanged(
        ChangeTypes.REMOVE_EXPONENT_BY_ONE, node, newNode);
    }
    return Node.Status.noChange(node);
  }
docs: If `node` is of the form x^1, reduces it to a node of the form x. Returns a Node.Status object.