code: function sortCharClass(a, b) {
    const aValue = getSortValue(a);
    const bValue = getSortValue(b);
  
    if (aValue === bValue) {
      // We want ClassRange before Char
      // [bb-d] -> [b-db]
      if (a.type === 'ClassRange' && b.type !== 'ClassRange') {
        return -1;
      }
      if (b.type === 'ClassRange' && a.type !== 'ClassRange') {
        return 1;
      }
      if (a.type === 'ClassRange' && b.type === 'ClassRange') {
        return getSortValue(a.to) - getSortValue(b.to);
      }
      if (
        (isMeta(a) && isMeta(b)) ||
        (isControl(a) && isControl(b))
      ) {
        return a.value < b.value ? -1 : 1;
      }
    }
    return aValue - bValue;
  }
docs: Sorts expressions in char class in the following order:
  - meta chars, ordered alphabetically by value
  - chars (except `control` kind) and class ranges, ordered alphabetically (`from` char is used for class ranges)
  - if ambiguous, class range comes before char
  - if ambiguous between two class ranges, orders alphabetically by `to` char
  - control chars, ordered alphabetically by value
  @param {Object} a - Left Char or ClassRange node
  @param {Object} b - Right Char or ClassRange node
  @returns {number}