function getLeadingComment(path) {
    const siblings = getSiblings(path);
    let node = path.getNode();
    let prev = siblings.find((child) => child.end === node.start);
    while (prev) {
        if (prev.type === 'Comment' &&
            !isIgnoreStartDirective(prev) &&
            !isIgnoreEndDirective(prev)) {
            return prev;
        }
        else if (isEmptyTextNode(prev)) {
            node = prev;
            prev = siblings.find((child) => child.end === node.start);
        }
        else {
            return undefined;
        }
    }
}
Returns the comment that is above the current node.