code: function checkInclude(i) {
    let l;
  
    if (i >= tokensLength) return 0;
  
    if (l = checkIncludeWithKeyframes1(i)) tokens[i].include_type = 9;
    else if (l = checkInclude1(i)) tokens[i].include_type = 1;
    else if (l = checkInclude2(i)) tokens[i].include_type = 2;
    else if (l = checkInclude3(i)) tokens[i].include_type = 3;
    else if (l = checkInclude4(i)) tokens[i].include_type = 4;
    else if (l = checkIncludeWithKeyframes2(i)) tokens[i].include_type = 10;
    else if (l = checkInclude5(i)) tokens[i].include_type = 5;
    else if (l = checkInclude6(i)) tokens[i].include_type = 6;
    else if (l = checkInclude7(i)) tokens[i].include_type = 7;
    else if (l = checkInclude8(i)) tokens[i].include_type = 8;
  
    return l;
  }
docs: Check if token is part of an included mixin (`@include` or `@extend`
  directive).
  @param {number} i Token's index number
  @return {number} Length of the included mixin