code: function checkDeclaration2(i) {
    const start = i;
    let l;
  
    if (i >= tokensLength) return 0;
  
    if (l = checkPropertyDelim(i)) i++;
    else return 0;
  
    if (l = checkProperty(i)) i += l;
    else return 0;
  
    if (l = checkValue(i)) return i + l - start;
  
    if (l = checkSC(i)) i += l;
  
    if (l = checkValue(i)) i += l;
    else return 0;
  
    return i - start;
  }
docs: Check if token is part of a declaration (property-value pair)
  @param {number} i Token's index number
  @return {number} Length of the declaration