isAttached(attachment) {
        const attachmentState = this.robot.state.getFirstMatchingAttribute({
            attributeClass: stateAttrs.AttachmentStateAttribute.name,
            attributeType: attachment
        });

        if (attachmentState === null) {
            return false;
        }

        return attachmentState.attached;
    }
@private
@param {string} attachment
@return {boolean}